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2022 | Buch

Advances in Road Infrastructure and Mobility

Proceedings of the 18th International Road Federation World Meeting & Exhibition, Dubai 2021

herausgegeben von: Dr. Amin Akhnoukh, Prof. Dr. Kamil Kaloush, Mag. Magid Elabyad, Brendan Halleman, Nihal Erian, Samuel Enmon II, Cherylyn Henry

Verlag: Springer International Publishing

Buchreihe : Sustainable Civil Infrastructures


Über dieses Buch

This volume focuses on recent advances in the planning, design, construction and management of new and existing roads with a particular focus on safety, sustainability and resilience. It discusses field experience through case studies and pilots presented by leading international subject-matter specialists. Chapters were selected from the 18th International Road Federation World Meeting & Exhibition, Dubai 2021.



Pavement Testing

A New Low-Activity Nuclear Density Gauge for Compaction Control of Asphalt, Concrete, Soil, and Aggregate Layers in Road Construction

Density is used as a measure for quality control of compaction of asphalt, concrete, soil, and aggregate layers in road construction. For in-place density measurements, nuclear gauges have been successfully used for decades because of the good measurement properties, such as precision and sensitivity of the nuclear technique. The technique is nondestructive and is a direct method for measuring density. The widespread use of nuclear gauges has been limited because of the nuclear regulatory requirements associated with the usage of radiation sources.To overcome this limitation, in 2016, a nuclear gauge using a low-activity radiation source and a high-efficiency detector was developed. This gauge used mostly for compaction testing of soil and aggregate layers and is exempt from the nuclear regulatory requirements in the United States. Using similar technology, a new nuclear gauge was developed recently to measure density of asphalt and concrete layers in addition to soil and aggregate layers. This gauge is also exempt from the nuclear regulatory requirements in the United States. The new gauge has the option of using a separate probe based on an electromagnetic method for measuring the moisture content of soils and aggregates. This paper presents the design features, measurement properties, and safety aspects of the new nuclear gauge and its associated moisture probe. Comparison of the new low-activity nuclear gauge and a conventional nuclear gauge for measurement of density of asphalt layers, and density and moisture of soil and aggregate layers of thickness up to 30-cm (12-in.) are also presented.

Linus Dep, Robert E. Troxler, William F. Troxler Jr.
A Study into the Benefit and Cost-Effectiveness of Using State-of-the-Art Technology for Road Network Level Condition Assessment

Pavement condition assessment data is the cornerstone of any pavement management system (PMS). It enables expenditure to be optimally utilized to maximize benefit and reduce costs. The accuracy and frequency of the data plays a crucial role in the selection of appropriate repair measures to not only improve the road network condition but prolongs the effects of the improvement.Over the past decade, the manner in which this data is gathered has transformed from being based purely on visual condition assessments into the use of semi and full automated measuring devices using lasers and digital imaging which drastically reduces subjectivity of data and increases collection efficiency.This study investigates and quantifies the economic lifecycle benefits of using devices such as the Network Survey Vehicle (NSV), Falling Weight Deflectometer (FWD) and Traffic Speed Deflectometer Device (TSDD) in comparison to that using manual visual condition assessment methods. These devices measure the structural and functional condition of the pavement and include parameters such as roughness, texture depth, rut depth, deflection, digital imaging and automated crack detection by the TSDD.HDM-4 has proved to be the ideal tool to predict life cycle cost and benefit of a road network and has been utilized in this study. The outcome of the study shows that the cost state-of-the-art road assessment technology used for network level condition assessment is justified by the benefit or savings in expenditure by road agencies.Whilst this study is based in South Africa, the results and findings will be applicable globally.

Herman Visser, Simon Tetley, Tony Lewis, Kaslyn Naidoo, Tasneem Moolla, Justin Pillay

Asphalt Pavement Innovations

Paths to Successful Asphalt Road Structures Performance Based Specifications for Hot Mix Asphalt

Current and future challenges in road engineering, including but not limited to increasing heavy goods traffic, scarce natural resources, climate crisis and shrinking public budgets, bring the urgent need for economically and ecologically efficient road pavements. To ensure long-lasting roads, high-quality mix design and quality assurance/control are crucial preconditions. This includes realistic simulation of the stress situation in the field by state-of-the-art laboratory testing of materials.Therefore, this paper focuses on performance-based test methods that address the effective mechanical characteristics of bituminous materials, which may be introduced into national requirements within the framework of European HMA specifications. These test methods comprise low-temperature tests, i.e. the tensile stress restrained specimen test (TSRST) or the uniaxial tensile strength test (UTST), stiffness and fatigue tests, i.e. the four-point bending beam test (4PB) or the uniaxial tension-compression test (DTC), as well as methods to determine permanent deformation behaviour employing dynamic triaxial cyclic compression tests (TCCT).These tests are used for the performance-based mix design and subsequently implemented in numerical pavement models to predict in-service performance. Thus, load-induced stresses and mechanogenic effects on the road structure can be simulated, and improved predictions of the in-service performance of flexible pavements over their entire service lives are possible.

Bernhard Hofko
Study on Rejuvenators and Their Effect on Performance Characteristics of an Asphalt Concrete Containing 30% Reclaimed Asphalt

The use of reclaimed asphalt has become a common practice and necessity in many developed countries whereas there are several options how to deal with elevated content of such material. Well-developed are solutions where reclaimed asphalt is cold fed by up to 20%. Higher portions of reclaimed asphalt are still challenging and need additional focus to become a regularly used standard. Quite common in last few years has been the use of rejuvenators, which are special chemical compounds helping to partly restore the degraded bitumen and secure sufficient performance behavior of asphalt mix containing higher portions of reclaimed asphalt. Recent study focused on use of several market-established rejuvenators and some newly developed variants, which are predominantly based on renewable materials. A typical asphalt concrete AC16 has been selected and 30% virgin aggregate was replaced by reclaimed asphalt of 0/8 mm grading. A scenario with 50% reclaimed asphalt was assessed too but is not part of this paper. Rejuvenators were added in a content between 5–7% of the degraded bitumen content present in the reclaimed asphalt. Functional tests have been performed focusing on water susceptibility, deformation behavior (stiffness) and resistance to crack propagation. At the same time bitumen extracted from the reclaimed asphalt was mixed with rejuvenator and selected bitumen tests were performed to find or confirm potential relations between binder and asphalt mix behavior.

Pavla Vacková, Majda Belhaj, Jan Valentin, Liang He
Sustainable Use of Cool Pavement and Reclaimed Asphalt in the City of Phoenix

In 2020, The City of Phoenix began work on two projects to improve sustainability and livability: The Cool Pavement Pilot Program (CPPP) and Reclaimed Asphalt Pavement (RAP) trials.Faced with long-term projections of rising urban temperatures and an increased frequency of dangerous heat waves, jurisdictions are seeking ways to reduce pavement temperatures to improve sustainability and resilience. The City initiated a pilot program to evaluate a colored pavement coating, building off previous work in Los Angeles. The City enlisted help from Arizona State University researchers and scientists for a comprehensive evaluation of the CPPP. The project includes thirty-six miles of pavement across the City. After extensive public outreach, installation occurred between June and October 2020. The CPPP resulted in unprecedented media interest, positioning Phoenix in the spotlight for technology and innovation both locally and nationally. Cool Pavement may measurably improve comfort and livability in the City.In 2019, approximately twenty-one percent of all asphalt pavement in the United States included Reclaimed Asphalt Pavement (RAP). The City’s stance on RAP recently changed because of improved methodologies for ascertaining the quality and performance of RAP and is exploring its use. The City has partnered with Arizona State University to study and test the feasibility of using RAP. Trial projects have been constructed with RAP in slurry seals, microsurfacing and overlays. The City also developed two sites to create RAP from asphalt millings generated in day-to-day maintenance operations.

Ryan Stevens
Optimizing the Adhesion Quality of Asphalt Binders Based on Energy Parameters Derived from Surface Free Energy

In the search to improve the performance and response of asphalt binders for the fabrication of asphalt mixtures, different additives are currently added either to the asphalt binder or the asphalt mixture, whose effect is mainly evaluated by macroscopic tests. However, less frequently these analyzes focus on the evaluation of the microscopic behavior of the mixture, its components, or their interaction. In this context, the objective of this study is to evaluate the feasibility of optimizing the adhesion quality of asphalt binder-aggregate interfaces for both modified- and residual-asphalt binders, based on the surface free energy (SFE) of the constituent materials. For this purpose, this study evaluated asphalt binders—here called as modified-asphalts—obtained from the mixture of neat asphalt binder and: (i) natural mineral filler, (ii) manufactured filler, and (iii) warm mix asphalt additives; in addition, residual-asphalts obtained from asphalt emulsions were analyzed. The SFE components of all asphalt binders were determined by means of the Wilhelmy plate method, whereas the Universal Sorption Device was used to determine the SFE of the five aggregates characterized. Analysis of four energy parameters—derived from the SFE components—suggests that optimization of the adhesion quality of asphalt binder-aggregate interfaces formed with modified-asphalt binders is feasible by using a specific optimal modifier dose. Similar results were reported for some aggregate-residual-asphalt combinations. Future research is recommended to verify at the asphalt mixture level the possible improvement in its quality of adhesion, based on the optimal doses here reported.

Allex E. Alvarez, Lady D. Vega
Estimating Asphalt Film Thickness in Asphalt Mixtures Using Microscopy to Further Enhance the Performance of UAE Roadways

The asphalt binder coating aggregate particles in hot-mix asphalt (HMA) is considered the key factor that is responsible for the durability of asphalt mixtures and hence the service life of Asphalt Concrete (AC) layers of asphalt pavements. This portion of the asphalt binder is what so-called the asphalt film in the mixture. Estimating the thickness of this film experimentally has been a challenging process for asphalt researchers as it requires high accuracy and needs very careful procedures in the analysis part. In the current Superpave specifications, the asphalt film thickness is not considered as one of the mix design requirements for asphalt mixtures but instead, the Voids in Mineral Aggregate (VMA) is considered in the mix design.This research offers a new methodology to image and analyze the micro-structure of the asphalt mix for quality and performance purposes. Using a stereo microscope is preferred to SEM, mainly because the electrons in the SEM device detect the fillers with a resolution like the asphalt, providing a challenge when thresholding the image. The binary image produced is then analyzed to obtain the aggregate shape descriptors and voids area. Measurements of the asphalt thickness can only be done manually, a single and two step measurement process is explained in the paper.

Alaa Sukkari, Ghazi Al Khateeb, Waleed Ziada, Helal Ezzat
Effect of Crumb Rubber and Polymer Modifiers on Performance Related Properties of Asphalt Binders

Crumb rubber modified bitumen (CRMB) has been generally used to improve the high temperature performance of asphalt mixtures in the past decades. Besides, the addition of a certain percentage of polymers into asphalt binders has been known to enhance their engineering characteristics. This study aims to investigate the rutting and fatigue cracking performance of CRMB, and polymer modified asphalt binders by means of Dynamic Shear Rheometer (DSR), Multiple Stress Creep Recovery (MSCR), and Bending Beam Rheometer (BBR). Different percentages of Crumb rubber (5, 10, 15, and 25%) obtained using the ambient grinding process were blended with a PG70-16 asphalt binder using the wet process. Small percentages ranging from 0.5 to 2% of polymers (LSBS, PPA, Elvaloy, and CBE) were added to a PG64-16 asphalt binder. It is demonstrated that mixing a specified percentage of crumb rubber from scrap tires, with the proposed optimized laboratory protocol, will result in an improved high-temperature performance reflecting higher rutting resistance complying with certain needs of regions with warm climates, especially the Mediterranean area. However, crumb rubber content should be restricted to 10% to limit the effect of the CR on the low-temperature performance grade. In the case of polymer modification, significant benefits were observed for rutting resistance of the resulting modified asphalt binders without jeopardizing fatigue cracking resistance criteria.

Joseph Dib, Nariman J. Khalil, Edwina Saroufim

Road Safety Leadership

How Do Best Performing Countries in Road Safety Save Lives on the Roads? Lessons Learned from Case Studies in Singapore

We are still in an era where road engineers are focused only on design standards and creating roads for motor vehicles. It is necessary to change this mentality in order to have safer streets, and Singapore is a good example of success story for building a safer road infrastructure for safer communities, especially through the coordination of different institutions. Singapore is considered one of the best performing countries globally and regionally in terms of road safety. Road safety management rules and regulations implemented in the country have resulted in significant strides in managing the effects of collision factors related to roadway design, human behavior, and vehicle attributes. As a result, road safety statistics have shown that fatalities on the Singapore road network have been steadily declining over the past decade. This is leading to a desire on the part of neighboring countries to follow Singapore’s example and learn from its experience. This paper will show examples and case studies on why Singapore roads are not only considered the safest in the region, but they also rank among the safest globally, through a strong road safety management overseeing safe road infrastructure, enforcement, vehicle safety.

Alina Florentina Burlacu, Emily Tan
Data for Road Incident Visualization, Evaluation, and Reporting (DRIVER): Case Studies of Cebu, Philippines and the Asia-Pacific Road Safety Observatory (APRSO)

Robust crash data systems are key to understand the nature and magnitude of the road safety problem and to propose appropriate solutions. However, resource constrained governments oftentimes lack adequate data systems or tools for collecting, storing, managing, analyzing, and reporting historic crash data. As a result of previous World Bank efforts, and with the aim of tackling this problem, a free open-source system for recording and visualizing geo-referenced crash data was developed and piloted. This system, Data for Road Incident Visualization, Evaluation, and Reporting (DRIVER), does not have licensing costs for clients and can be deployed by agencies interested in improving their crash data management systems. Originally in response to the absence of sound crash data in the Philippines, the World Bank, working with the Government of the Philippines (GoP), developed and piloted DRIVER starting 2014. After successfully completing the pilot phase in Cebu, and later in Manila, all relevant government agencies signed a memorandum of understanding (MOU) on data input, sharing, and use in 2016, marking the beginning of DRIVER as the national level road crash data management platform. The GoP is working to scale-up DRIVER at national level with World Bank support, with pilots starting in other countries around the world. This tool complements the work recently started under the Asia-Pacific Road Safety Observatory (APRSO) which aims to support countries in generating reliable crash data. DRIVER’s successful implementation reinforces the growing demand for data and emphasizes the need for localization, capacity-building, and developing robust road safety institutional arrangements.

Florentina Alina Burlacu, Miguel Enrico III Cabag Paala, Veronica Ines Raffo, Juan Miguel Velasquez Torres

Road Financing Strategies

Is a Further Increase in Fuel Levy in Kenya Justified?

Road transport is the predominant transportation mode in Kenya, contributing to about 9% of the GDP. Increased expenditure in roads has seen road assets become a significant portion of public investments that must be preserved. In Kenya, funds for road maintenance are primarily derived from fuel levy, which is charged per liter of petroleum imported. Despite the recent doubling of fuel levy charge, it is still inadequate for the entire network maintenance needs. This has prompted calls for a further increase in fuel levy in line with the government’s “user pay” policy, much to motorists’ chagrin. This study seeks to assess whether these calls are justified by comparing the benefits of increasing maintenance expenditure versus the road user cost (RUC) savings.The study methodology involved undertaking network strategy analysis using the HDM-4 model. The model was used to quantify the optimal network maintenance needs, network performance under different budget scenarios, and the impact of increased maintenance funding on RUCs.The study revealed that Kenya needs to double its fuel levy from the current US$ 0.18 per liter in order to meet its entire network maintenance requirements. It also revealed that every dollar invested in road maintenance translates to RUC savings of about US$ 5.53.However, fuel levy charging is under threat as road user charging is becoming “politically unpopular”. Also, vehicle fleets are switching to alternative fuels, and engine efficiencies are improving, leading to declining fuel consumption hence the need to explore alternative sources of maintenance financing.

Evans Omondi Ochola, Jennaro Boniface Odoki

Bridge and Structural Management

Aerial Robotic System for Complete Bridge Inspections

Bridge inspections have a large variety of procedures to ensure the safety of its facilities and personnel, and at the same time tightly budget constraints. These procedures involve extensive inspections, most of which should be performed at height and using both cameras and other sensors that require to be in contact with the surfaces being inspected. Then, bridge inspections traditionally require access to specific inspection points using man-lifts, cranes, scaffolds, or rope-access techniques, which increments importantly the costs of these inspections.This work will present a system formed by two drones that will perform complete inspection operations in bridges in less time, reducing costs, improving quality of the inspection, and increasing safety of operators. The first one is an aerial robot that can obtain pictures of the overall bridge fully autonomously thanks to a GPS-free navigation system. The second one is the AeroX drone platform, a novel solution for inspection of difficult access areas. The AeroX can perform contact inspection due to its robotic contact device, which is equipped with an end-effector. Finally, both drones will be presented with videos of the validation experiments.

Antidio Viguria, Rafael Caballero, Ángel Petrus, Francisco Javier Pérez-Grau, Miguel Ángel Trujillo
Damage Inspection, Structural Evaluation and Rehabilitation of a Balanced Cantilever Bridge with Center Hinges

A main objective of the present investigation is to carry out bridge inspection and evaluation, and determination of structural rehabilitation of Phra Pinklao Bridge, having structural configuration of a balanced cantilever bridge with center hinges. The bridge structure is a 3-span, continuous prestressed concrete box girder with a total length of 280 m and a width of 26.6 m supporting 6 traffic lanes. The investigation tasks include 1) bridge visual inspection, 2) measurement of bridge alignment and profile, and joint movements, 3) bridge load test and behaviors measurement, 4) structural analysis and load-rating evaluation, and 5) appropriate bridge rehabilitation plan. Based on the results of bridge inspection, structural damages of the center hinge bearings in a critical state are reported. The damages include permanent deformation of stayed plates and plunger edges of the hinge bearings causing the bearing movement to be restrained and direct impact on serviceability and load-carrying behaviors of the bridge structure. Responses of the bridge structure and identification of any structural damages and deficiency are examined by employing diagnostic load testing under predetermined loading. The results of load-rating evaluation yielding sufficient load-carrying capacities of the existing box girder are reported. According to the investigation carried out, it can be found that appropriate implementation of the planar hinge bearing concept yields a most suitable and effective method for the center hinge bearing replacement of the bridge structure.

Chawalit Tipagornwong, Koonnamas Punthutaecha, Peerapat Phutantikul, Setthaphong Thongprapha, Kridayuth Chompooming
Reinforcement of Scoured Pile Group Bridge Foundations with Spun Micro Piles

This article demonstrates an approach to reinforce the bridge’s foundations, of which its safety factor had been reduced to a dangerous level by scouring, with the use of spun micro piles. The bridge was built more than 30 years ago at Dong Pa Lan, Mae Fai Subdistrict, San Sai District, Chiang Mai Province, Thailand. The Department of Rural Roads investigated the existing piles’ lengths embedded in the soil using Parallel Seismic Test and then recalculated the capacity of the foundations. The calculation suggested that one of the foundations had a safety factor of 1.04, which was considered extremely dangerous from a geotechnical engineering aspect since a value higher than 3.0 is typical. A collapse would occur if the bridge was subjected to more scour and traffic without reinforcement. The department examined a few solutions to the problem considering limitations on the construction space, necessity of traffic during the repairing process, cost, and safety for the construction, and then decided to reinforce the foundations with spun micro piles. The process began with pressing the piles around the old foundations into the stiff soil layer by using hydraulic jacks. The weight of the superstructure was transferred by temporary steel structures to the new micro piles. The bridge was then lifted a little to pre-load the piles. Finally, concrete columns reinforced with steel tubes were cast to connect the old foundations with the micro piles. The result suggested that the spun micro piles were able to support the weight of the bridge and complied with the design criteria and engineering standards.

Apichai Wachiraprakarnpong, Juti Kraikuan, Jirasak Watcharakornyotin, Thanwa Wiboonsarun
Repair of Settled Pile Bent Bridge Foundations with Spun Micro Piles

This article demonstrates an approach for reinforcing bridge’s foundations, which had been settled from scouring, with the use of spun micro piles to substitute the existing piles. The bridge was built 27 years ago crossing Ranae Canal in Phipun District, Nakhon Si Thammarat Province in the southern region of Thailand. The bridge has eight pile-bent foundations. The Department of Rural Roads investigated the bridge in 2020 and found that two foundations in the middle of the channel settled down by 7 and 10 cm from the initial elevation, causing a shift in the bridge’s horizontal alignment. This deflection significantly reduced the capacity of the bridge and would cause danger if it was still opened for traffic. The department examined a few solutions to the problem considering limitations on the construction space, necessity of traffic during the repairing process, cost, and safety during construction, and then decided to reinforce the foundations with spun micro piles. The process began with driving the micro piles around the old foundations and constructing temporary structures to transfer the weight of the bridge to the new piles. The superstructure of the bridge was then lifted using hydraulic jacks against the load-transferring structures to obtain the desired level. The old concrete columns were replaced by the new composite ones. Finally, new reinforced concrete foundations were cast on the micro piles to support the bridge. The result suggested that the spun micro piles were able to support the weight of the bridge and complied with the design criteria and engineering standards.

Apichai Wachiraprakarnpong, Juti Kraikuan, Wichai Yu, Pawin Ritthiruth
Overview of Integral Abutment Bridge Applications in the United States

Integral abutment (IA) bridges have been successfully used in constructing highway bridges by different State Departments of Transportation (DOTs) in the United States over the past 60 years. IA bridges main advantages include the absence of construction joints which expedites the bridge construction process, increase bridge redundancy (improve seismic performance), and reduce the need to costly and laborious maintenance.Despite the afore-mentioned advantages, several DOTs have recently discontinued the IA bridge construction. Other state DOTs have conducted research to investigate the efficiency of IA bridge systems, their advantages, and disadvantages. This paper presents the history of IA bridge construction in the United States, different IA bridge construction techniques including IAs with Frame Abutments, Bank Pad Abutments, Embedded Wall Abutment, and Flexible Support Abutments, relevant advantages, and disadvantages. In addition to listing different maintenance activities required to maintain the IA bridge inventory within the United States. The presented information can be used by bridge design engineers, precast plants, and DOT personnel as a decision support tool to decide on the type of bridge system to be selected for new bridge projects.

Amin Akhnoukh, Rajprabhu Thungappa, Rudolf Seracino

Case Studies in ITS Development

Pacemaker Lighting Application to Prevent Traffic Congestion in a V-Shaped Tunnel and Provide Sustainable Operation: A Case Study: Eurasia Tunnel

Eurasia Tunnel is a V-Shaped TBM tunnel connecting Asian and European sides of Istanbul by reaching its deepest point at 106 m from sea level with a longitudinal slope of 5% in accordance with the highway standards. Free flow without any traffic congestion along the tunnel is one of key elements for traffic management not only traffic safety, but also good qualify of driving satisfaction in the tunnel. It has been observed that traffic flow speed decreases and light traffic congestions at the middle of the tunnel which cause increase in traffic density at the deepest point of the tunnel and the following uphill section due to sudden brake, wrong gear and/or wrong speed choices of the drivers. This study will discuss the Pacemaker Lighting application started in Eurasia Tunnel in June 2020, -which is a speed regulating moving light reflected on the ceiling of the tunnel by using LED fixtures-. This application aims to guide users for a smooth acceleration and following distance, to avoid undesirable traffic jams, to prevent potential traffic accidents, engine/transmission breakdowns and to decrease level of vehicle emissions. This paper also reports the sustainability provided by the system with the results of the application such as significant speed and efficiency increase in the Pacemaker Lighting Zone, significant decrease in the number of traffic speed decreases and vehicle emissions in 11 months of operation time.

Aşkın Kaan Kaptan, Murat Gücüyener
Real Time Multi Object Detection & Tracking on Urban Cameras

Processing video from urban video surveillance cameras requires the use of algorithms for multi-object detection and tracking on video in real-time. However, existing computer vision algorithms require the use of powerful equipment and are not sufficiently optimized to process multiple video streams simultaneously. This article proposes an approach to using the tracker in conjunction with the YoloV4 object detector for real-time video processing on medium-power equipment. Paper also presents the solution for difficulties that arise during work with optical flow. The results of the comparison of the accuracy and speed of image processing of the applied approach with such trackers as IOU17, SORT, KCF, and MOSSEE are also presented.

Rifkat Minnikhanov, Maria Dagaeva, Timur Aslyamov, Tikhon Bolshakov, Emil Faizrakhmanov
Effective Advanced Warning for Connected Safety Applications - Supplementing Automated Driving Systems for Improved Vehicle Reaction

Given the rapid pace of modern technological advancements, the public should expect and demand measurable improvements to highway safety. Yet, it is not so clear how much improvement may be anticipated. Government organizations such as the U.S. Department of Transportation (U.S. DOT) and National Highway Traffic Safety Administration (NHTSA) have already spent decades and millions of dollars researching proper markings, alerting systems, and safety distances to help reduce collisions and other incidents on public roadways. While clearly this effort has had great impact, there are limiting factors that continually constrain the ability of traditional methods to significantly reduce the number of collisions. Such factors include driver behavior aspects such as reaction time, sudden maneuvers, and traffic violations, plus infrastructure aspects such as malfunctioning signals, inadequate signage, and non-standard road design. As increased numbers of connected and automated vehicles (CAV) are introduced into the traffic stream, and advanced safety applications are continually improving, the industry envisions a major decline in incidents across the board. This paper details the limiting factors to why a sizable reduction of incidents is not possible with conventional resources and introduces the framework for adding advanced warnings into connected safety applications in existing vehicles, such as red-light violation warning (RLVW), to achieve measurable results. Further, the paper then applies this same model for use within automated driving systems (ADS). More than just a technological examination, this paper also predicts the expected impact to roadway incidents.

Gregory M. Baumgardner, Rama Krishna Boyapati, Amudha Varshini Kamaraj

Traffic Planning and Forecasting - 1

A Case Study of Rural Freight Transport – Two Regions in North Carolina

Rural and urban transportation needs are known to be different. Our objective was to understand how infrastructure investments could help rural areas of North Carolina with economic development. For many planners and economic developers, freight growth is seen as the physical manifestation of a strong economy but planning for freight is challenging. For us to understand the rural needs better, we conducted a socio-economic study, an economic analysis, and two workshops. The workshops focused on two areas of the state, the deep southwest and the far northeast. These regions are among the most economically depressed and economic development through enhanced freight infrastructure could be very helpful.Due to the mountainous terrain in the deep southwest, the resiliency and reliability of the state’s transportation system is critical. Even more important than building new capacity, is ensuring the functionality of existing highway, rail, and aviation assets. The region does not act as one unit, but instead as a collection of many microeconomies that transcend county and state boundaries. The proximity of the far northeast to Norfolk and the eastern seaboard provides a comparative advantage for marine industries. The area is well-positioned to capitalize on economic growth related to a nearby metropolitan area in Virginia. Highway, waterway, and other transportation networks that connect the region’s business and population centers to the Norfolk region can facilitate economic growth.

Daniel J. Findley, Steven A. Bert, George List, Peter Coclanis, Dana Magliola
Traffic Delay Evaluation and Simulating Sustainable Solutions for Adjacent Signalized Roundabouts

Roundabouts are proven to be an excellent solution to enhance traffic safety in comparison with intersections. However, multilane roundabouts with more than four approaches do not yet have any clear recommendations for the traffic signal installation neither the type of solution that can be applied to improve the Level of Service (LOS). This paper aims to evaluate signalized roundabouts that have multilane with more than four approaches to help to find sustainable traffic congestion solutions. The PTV-VISSIM software was used to evaluate the current operational performance and simulate multiple solutions for improvement. Traffic and geometric data of two adjacent signalized roundabouts (Al-Kuwait roundabout and Government square) in Sharjah City were used for this study. The two roundabouts are connected through a one-kilometer road.The results showed that the current LOS of both roundabouts is “F,” and there is no significant effect on the operational performance from each roundabout on the other. Moreover, the suggested solution showed LOS “D” with a 58% reduction in vehicle delay and a 60% reduction in stop delay for Al-Kuwait roundabout. While the reduction on the Government square was 62% and 65% for the vehicle delay and in stop delay respectively with a Level of Service “D” Overall, there is an indication that the suggested solution can reduce traffic delay significantly at this type of roundabouts; however, further research is highly recommended to estimate the economic, environmental, and safety benefits of the suggested solution.

Mohamad Yaman Fares, Muamer Abuzwidah

Safe Roads by Design - 1

A Comparative Evaluation of the Safety Performance of Median Barriers on Rural Highways; A Case-Study

Safety barriers provide forgiving roadsides for highways while their test performance should comply with uniform norms, e.g. EN1317. When selecting a barrier type for a median, the dilemma frequently compares between in-situ concrete and other barriers. In-situ concrete barriers require less space for their installation and rare maintenance, while steel guardrails can deflect, but require a wider median and higher maintenance, with associated crash risks during repair roadworks. This study compared the safety performance of highways with various median barrier types, in Israel, aiming to provide a background for more effective use of safety barriers. The study examined four barrier types: Step-shaped in-situ, pre-cast concrete and steel guardrails, as new barrier types (which satisfy the EN1317), and old NJ-shaped in-situ barriers. The database included 558 km of non-urban Israeli highways. Negative-binomial regression models were fitted for predicting crashes, and differences in crash expectancy were evaluated for various barrier types, while controlling for traffic volumes and other road infrastructure characteristics. The results showed that, on dual-carriageway roads, sections with Step-barriers had a better safety level relative to those with NJ-barriers and, sometimes, to other barrier types. On motorways, the safety level of sections with Step-barriers was better or similar to that with NJ-barriers, with no difference compared to the pre-cast barriers, while sections with steel guardrails had a better safety level, particularly at traffic volumes over 40,000 vehicles. The economic evaluations showed benefits for replacing the old NJ-barrier by a Step-barrier, on dual-carriageway roads, and by steel barriers, on motorways.

Victoria Gitelman, Etti Doveh
Ascendi’s Safety Barriers Upgrading Program

Over the years, there have been some changes regarding road vehicle restraint systems, especially concerning the requirements and the selection criteria for its implementation.In Portugal, the guidance manual that set the requirements for the safety barriers in accordance with the EN1317 was published in 2010. At that time, most of the Ascendi’s network was already constructed and under operation, being the safety barriers applied based on the national requirements available at the time of the project.In order to evaluate the network compliance with the current established requirements, Ascendi carried out an upgrading program (Ascendi’s Safety Barriers Upgrading Program) that started in 2018 and will run until 2023.This paper will cover the Upgrading Program that was established, going through the challenges of its implementation that included the development and certification of a brand-new safety barrier for bridges with a 30 cm curb in cooperation with Road Steel Engineering, S.L.

Telma Silva, João Neves
Effectiveness of Cable Median Barriers in Preventing Cross Median Crashes and Related Casualties in the United States - A Systematic Review

The purpose of this systematic review is to assess whether installation of cable median barriers (CMBs) in some stretches of freeways in different states have been effective in preventing cross median crashes (CMCs) and related casualties in the United States. As the CMBs get increasingly installed on highways, they have been taunted as the preferred median barriers due to their combination of lower costs of installation compared to other types of barriers such as concrete barriers and their effectiveness in their intended use, i.e., providing median crossover protection by preventing cross median crashes. Several state departments of transportation (DOTs) have been installing CMBs for more than 15 years and some states have evaluated the performance of median cable barriers installed on their freeways. This study evaluated safety evaluation studies from 12 states that have performed the effectiveness studies of CMBs. Ten of these studies were before-after studies and nine of them showed effectiveness of CMBs. Reductions in outcomes across studies ranged from 24% to 93% for fatal and serious injury cross-median crashes and 50% to 91% for total cross-median crashes. However, increasing in outcomes ranged from 18% to 163% for possible injury and property damage only crashes of vehicles that primarily collided with the barriers but did not cross-over to the opposing lanes. Cable barriers have proved to be a valuable safety engineering tool effective in reducing fatalities and serious injuries due to crossover crashes on the states’ most heavily traveled roads.

Baraah Qawasmeh, Deogratias Eustace

Integrated Transport Planning

Transforming Infrastructure Projects Using Agile

Traditional project management processes, also referred to as waterfall processes, have been used for decades to manage infrastructure projects. Agile project management, first introduced by the software industry, and known for its adaptability, targets projects delivery using an iterative and/or incremental approach, thus improve project delivery time and cost.This research paper explores how road infrastructure projects, historically reliant on traditional project management processes, can attain benefits using the Agile set of principles and methods. With current challenges, high uncertainties and ever-changing and evolving customer requirements, there needs to be a more adaptive approach to managing and delivering road infrastructure projects to address changes in a timely and effective manner, while fostering collaboration among stakeholders. Agile can address these challenges by utilizing cross-functional teams which rely on retrospectives and continuous feedback from customers to improve team performance and enhance project outcomes and product delivery. The full benefits of Agile can only be exploited if there is a supporting organizational culture and active leadership participation.

Nihal Erian, Brendan Halleman
Savings Potential in Highway Planning, Construction and Maintenance Using BIM - German Experience with PPP

The digitalization of infrastructure planning in Germany is the current focus of an extensive infrastructure investment program running until 2030. Building Information Modeling technology has been supported by the Federal Ministry of Transport since 2015 and is mandatory for all newly started major projects since 2020.BIM is a process for creating and managing information on a construction project across the project lifecycle. One of the key outputs of this process is the Building Information Model, the digital description of every aspect of the built asset.The highway A7 is one of the main arterial roads in Germany. This will be widened in sections to 6 lanes. In the northern German state of Lower Saxony, a section was put out to tender as a Public-Private-Partnership-project (PPP project). The contract for approx. 60 km of construction planning, construction and maintenance over 30 years was awarded to a consortium of Eurovia (VINCI Autoroutes) at a cost of around €1 billion. The project will be planned, executed, and maintained using digital tools using the BIM framework.This report explains the entire value chain and highlights the use of a uniform, fully parametric BIM overall model. It shows how digital twin, design model and construction model are used on the construction site. The temporal processing, as well as quantity and cost accounting are dynamically adapted to the requirements of logistics, and material deliveries. The construction site reports progress on a weekly basis, while management at headquarters always has an overview of budget and time.

Veit Appelt
Demonstrating Connectivity and Exchange of Data Between BIM and Asset Management Systems in Road Infrastructure Asset Management

Road infrastructure asset management is currently facing rapid digital transformation opening up new opportunities for the application of data from both traditional and new data sources, the ability to integrate data across multiple Assets and the potential to improve efficiency in decision making throughout the asset lifecycle. However, there are challenges structuring, integrating, and linking data between different Assets and data sources – especially those data contained separately within asset management and BIM platforms. The CoDEC (Connected Data for Effective Collaboration) project aimed to address these challenges by creating a Data Dictionary to link/integrate static and dynamic data for “key” infrastructure assets (including road pavements, bridges and tunnels). Having proposed such a dictionary, the potential benefits offered for connecting and linking data have been shown in three pilot projects to demonstrate (1) how tunnel monitoring data can enrich BIM models of tunnels (2) how data from bridge sensors can be linked and visualised and (3) how highway data generated at construction in a BIM model can be linked to asset-management GIS for the operational phase. The results from these pilots present the challenges, lessons learned and practical benefits of linked data and semantic web technology to connect BIM to AMS and GIS platforms.

Sukalpa Biswas, John Proust, Tadas Andriejauskas, Alex Wright, Carl Van Geem, Darko Kokot, António Antunes, Vânia Marecos, José Barateiro, Shubham Bhusari, Jelena Petrović

Greening Road Projects

Road Construction Using Locally Available Materials

Road Construction in developing countries can be expensive. Therefore, an effective and a more affordable method is needed. Using local, indigenous, and in-situ materials are becoming necessary as the luxury of constructing asphalt mixing stations with a secured material supply chain for crushed aggregate and more does not always exist. Meanwhile, recently introduced environmental regulations bring additional constraints on traditional road construction practices.AggreBind’s soil stabilization products; RoadMaster RM1/RM2 and AggreBind AGB-WT/BT are unique, patented and patent-pending, water based, cost effective, environmentally friendly, cross-linking polymeric emulsions with or without a proprietary tracer that provides an excellent quality assurance tool for specifiers and contractors alike.This Paper investigates the influence of using AGB-WT on improving the load-bearing strength and shear-strength parameters, while expanding longevity of stabilization and creating water-resistance in roads constructed using primarily in-situ materials, including sub-soils, sands, mining waste and crushed construction waste.Reported results have proven that AGB-WT can provide stable and dust-free roads as well as stabilized base-layers for major highways passing the requirement of International Road Specifications. Moreover, it is concluded that the use of AGB-WT in soil stabilization or in stabilizing base-layers in road construction can reduce the cost of road construction by 40% to 60% and increase the in-situ load-bearing capacity by 400% to 600%. Results are documented in AggreBind’s Book of Civic Approvals and Independent Test Results.

Robert D. Friedman, Ahmed F. Abdelkader

Practical Applications of Big Data Science

Road Roughness Estimation Using Acceleration Data from Smartphones

The International Roughness Index (IRI) is a serviceability measure index for highway maintenance performance evaluation. At the Thailand Department of Highways (DOH), IRI is generally measured by Laser Profilers and Walking Profilers, which require experts to operate and process data. For the day-to-day road maintenance, real-time approximated IRI values are helpful to locate the damage area where roadwork is urgently needed. This study presents a simple method to estimate IRI from acceleration data collected from smartphones equipped with accelerometers. Acceleration data are segmented into 100-m sections and processed with the Fast Fourier Transform (FFT). For each 100-m road section, an average IRI is collected by using an accuracy Laser Profiler and compared with the processed acceleration data. The primary result shows that IRI has a linear relation with the sum of Magnitude of the FFT of the vertical acceleration obtained from the smartphones with the R-squared of 0.8745. In future, the DOH plans to extend this research findings and develop a smartphone application to collect real-time IRI for road maintenance management.

Arak Montha, Attaphon Huytook, Tatree Rakmark, Ponlathep Lertworawanich
Improving Traffic Safety by Using Waze User Reports

Road inspection regularity and existing types made by road maintenance crew have not been good enough to be aware what is really happening on the roads. Road users’ contribution in road traffic safety is very important to ensure fast reaction on different road hazards.It is important to ensure not only the most common ways to report road hazards on state roads by phone, by email and on social media, but also expand data sources options in modern and user-friendly way.Waze navigation application already had functionality to report road hazards – to warn other application users, but no one acted to solve these road hazards until someone reported them through existing communication channels supported by State Joint Stock Company Latvian Roads Maintainer and State Company Latvian State Roads.To ensure better road traffic safety and faster reaction time on road hazards solving, Latvian Roads Maintainer gained access to Waze report feed and made a system for analyzing and processing Waze data. As the result - Latvian Roads Maintainer can improve road safety by faster reaction to road hazards reported by Waze users.Today, up to 70% from total reports processed by Latvian Roads Maintainer are generated by Waze.

Raitis Steinbergs, Maris Kligis
A Glimpse into the Near Future – Digital Twins and the Internet of Things

A glimpse into the near future, digital twins are an exciting and innovative technology designed to maximize existing road assets. Digital twins offer organizations the opportunity to deliver leading-edge asset management capabilities and integrated analytics by unlocking the wealth of information stored in existing pavement and bridge management systems. These capabilities offer immense benefit to transportation agencies by ensuring efficient, reliable, and available asset information critical to operations and planning.This paper will offer a new perspective of capital investment strategy and maintenance operations. It will present a model for organizations to move beyond standard maintenance and operations and into a larger framework based on the Internet of Things (IOT). This will provide additional real-time intelligence about assets to enhance operations and maximize investments, while optimizing the total cost of ownership and state of good repair.Topics addressed in this paper include: A discussion of how organizations are preparing to deploy digital twins within an overall asset lifecycle management framework. Use case examples of how organizations are planning to deploy digital twins by integrating source systems of record (SSOR) such as pavement and bridge management systems. An overview of the services, products, and technologies employed. The latest thinking on asset management, including human factors, cyber and physical security, big data analytics, artificial intelligence (AI), and machine learning (ML).

Howard Shotz, James Birdsall

Long Term Pavement and Asset Performance - 1

Field Monitoring of Road Pavement Responses and Their Performance in Thailand

From late 2017 to mid of 2018, the Bureau of Road Research and Development, Thailand Department of Highways (DOH) in collaboration with the Faculty of Engineering, Kasetsart University initiated three comprehensive field instrumented pavement sections in order to fully understand the load carrying behavior and characteristics of typical Thailand road conditions. The novel sections included a rigid pavement in Nakorn Chaisri district, Nakorn Phathom province and two flexible pavements in Potaram district, Rachaburi province and Sapphaya district, Chainat province. As part of national highway network under the responsibility of the DOH, each section adjacent to permanent weigh station and weigh-in-motion (WIM) system was uniquely researched and developed based on local Thailand conditions.

Auckpath Sawangsuriya
Supplementary Cementitious Materials in Concrete Industry – A New Horizon

Supplementary Cementitious Materials (SCMs) market share in ready mix concrete industry has been significantly increasing during the past 2 decades. SCMs as silica fume, fly ash, quartz flour, and blast furnace slag are currently used in partial replacement of conventional portland cement to improve mix properties including flowing ability, compressive strength, modulus of elasticity, and long-term performance. The main advantages of SCMs are attributed to the contribution of SCMs to the formation of additional concrete binder and the improved packing order of the cementitious material matrix.Due to the afore-mentioned advantages, SCMs have been used in developing ultra-high-performance concrete, also known as reactive powder concrete. SCMs are successfully used in developing non-proprietary high-performance mixes used in high-rise construction and in fabricating high performance precast/prestressed bridge girders for new infrastructure projects. This paper displays the advantages of SCMs, and present different proprietary and non-proprietary mixes developed by incorporating SCMs, and their effect on different concrete properties. The wide spread of SCMs in concrete industry would potentially increase construction projects life span and minimize the need to routine maintenance.

Amin Akhnoukh, Tejan Ekhande
Long Term Anti Corrosion Measures for Magosaki Viaduct by Cover Plate Method

Magosaki Viaduct is a three-span continuous steel plate girder bridge with a total length of 134 m and has served for 35 years since opening in 1985. The viaduct is an approach to the Ohnaruto Bridge crossing the Naruto Strait where corrosion environment is harsh. Because of the wide carriageway, the viaduct has 14 main girders and thus has a large number of members and massive area to be repainted. Repainting works had been implemented twice so far in 1999 and 2008.By the comparison of long-term anti-corrosion measures, a cover plate method, in which the whole girders are covered with panels, was selected. This method is advantageous in maintenance work because maintenance personnel can walk on the cover plate as the permanent scaffold and approach the main girders and underside of the road deck for proximity inspection. Besides it was found that this method would provide better anti-corrosion performance and need less life cycle cost than repeating full repainting. Execution of the method started in 2017 and completed in 2018.In order to evaluate the anti-corrosion performance of the method, relative humidity in the cover plate and the amount of adhered salt on the main girders were measured in the next year of the installation. As a result, it was confirmed that the relative humidity was comparatively stable and the amount of salt did not increase.This paper reports a study on long-term anti-corrosion measures, and its design, installation work and evaluation of anti-corrosion performance of the cover plate method.

Hiromasa Kobayashi, Yukio Usuda, Yuki Kishi, Yukio Nagao
Degradation of Friction Performance Indicator Over the Time in Highways Using Linear Mixed Models

Pavement Management Systems use models describing performance indicators and can be used to plan future maintenance and rehabilitation activities taking into account the safety and economic requirements. The COST Action 354 (Long Term Performance of Road Pavements), with the participation of experts from 15 European countries, has established a list of seven performance indicators. Skid resistance and texture are interrelated in the sense that texture can be considered to be one of the explanatory variables of skid resistance and both have a major bearing on road safety.Using the database provided by a Portuguese motorway concessionary, this study aimed to develop and validate linear mixed-effects models to describe the degradation of friction performance indicator, throughout the time, based on the formula established by COST, and identify whether the traffic, climate conditions, pavement structure, and geometric characteristics of the highway influence that behavior. To accomplish these main objectives, linear-mixed models with two random effects (one in the intercept and another associated with the slope in the Time variable) were considered for a 2-level data set (level 2 distinguishes the road sections and level 1 represents the repeated measures made over time). Two approaches were made: a model that includes only the variables inherent to traffic and climate conditions and another including the factors inherent to the highway characteristics.Results confirm that the traffic, climate conditions, pavement structure, and geometric characteristics of the highway influence the degradation of friction performance indicator.

Adriana Santos, Elisabete Freitas, Susana Faria, Joel Oliveira, Ana Maria A. C. Rocha

Road Safety Risk Diagnosis

Application of an Innovative Network Wide Road Safety Assessment Procedure Based on Human Factors

Often the identification of critical road segments relies on accidents as primary data. Nevertheless, accidents data are sometimes prone to errors. Moreover, relying on accidents, means waiting for them to occur before intervening. A modern road administration must intervene before accidents occur to save lives. Furthermore, it is nowadays proven that drivers’ behaviour is the leading accident influencing factor. Thus, it is crucial to deepen the analysis of the road-driver interaction by means of application of human factors’ principles to road safety. This means to judge how much the road is perceived by the driver and influences their behaviour. This helps to identify which are the triggering factors of accidents. This paper proposes a new analysis procedure which allows to make a network safety assessment and screening considering the human factors aspects. The process relies on road visual surveys and evaluations which allows to make a more detailed and proactive analysis of the road. Furthermore, the data required to implement the analysis are few and this makes it suitable to use also when data are hardly available (e.g., low- and middle-income countries). The paper presents the application of the procedure to three different road stretches of a total length of about 38 kms: one in Italy, one in Germany and one in Slovenia. The application of the procedure demonstrates that it can be easily applied by Human Factors trained inspector and that it may provide a ranking of the network suitable to identify the most critical section of the network.

Andrea Paliotto, Monica Meocci, Valentina Branzi
A Review of the Spatial Analysis Techniques for the Identification of Road Accident Black Spots and It’s Application in Context to India

A Road accident is an unexpected negative outcome of growth in the transportation infrastructure sector. Identification of road stretches where accidents occur frequently (also known as Accident Black spots) is the first step towards development of a safer road network. Over the past decades, several analysis tools and techniques have been adopted to identify accident black spots. Among these tools, Geographic Information System (GIS) stands out for its ability of not only storing and presenting data spatially but also for performing complex spatial analysis using statistical tools that rely on geographically referenced data.The paper presents GIS Approach to examine spatial patterns of road accidents and determine if they are spatially clustered, dispersed or random. The paper discusses the various spatial analysis techniques that have been applied in the past by Researchers worldwide in a chronological order for the identification of accident black spots. Spatial Auto-correlation Techniques such as Moran’s I and Getis-Ord (Gi) statistics have been discussed with an example from Indiana USA to examine spatial patterns and cluster mapping of accidents. Examples of application of Kernel Density Estimation (KDE) have been illustrated using previous research conducted on Des Moines city of Iowa State in USA, Melbourne in Australia.The paper also gives a comparative analysis of the three techniques i.e., Moran ‘I, Getis-Ord and KDE. At last the Paper discusses the road accident scenario in India and the scope of application of GIS techniques in Indian Cities for identification of road accident black spots.

Shawon Aziz, Sewa Ram
Road Network Safety Screening of County Wide Road Network. The Case of the Province of Brescia (Northern Italy)

Although EU roads are the safest in the world, the target of halving the road deaths by 2020 was not achieved. Road Infrastructure Safety Management procedures are key to improve road safety performances, and their implementation is required for primary road networks. Specifically, Road Network Screening enables to apply a wide-level analysis to identify the most critical segments of the network, and direct in-depth investigations more efficiently. Crash prediction models (CPMs) are extremely useful tools for quantitative road safety analysis, and road network screening can greatly benefit from their application. The Highway Safety Manual (HSM) is one of the main references worldwide, but the reported models are subjected to transferability issues due to their site-specific formulation. Most of previous studies on CPMs focused on HSM calibration models or investigated the effect of several factors over the crash frequency on specific road type. However, to our knowledge, Europewide few attempts were performed to develop a road network screening by mean of CPM. This paper covers these gaps by developing a specific CPMs to screen county-road network and identify most critical segment. The model was applied to the main road network of the Province of Brescia (Northern Italy). Few, but significant variables were identified in the model and maps were produced to rank the road network based on the crash frequency values. This model can serve as a relevant decision support tool for all bodies responsible in the definition of road safety interventions and related resources allocation, prior than crashes occur.

Michela Bonera, Benedetto Barabino, Giulio Maternini
An iRAP Based Risk Impact Analysis at National Highway-1 for a Proposed Route Connecting Coastal Areas of Bangladesh

The coastal areas of Bangladesh are poorly connected with the mainland only by waterways halting their economic growth and ability to exacerbate the potential tourism sector. According to the World Travel and Tourism Council (WTTC) and United States Agency for International Development (USAID), the tourism and fisheries sector contributes only 2% and 4.4% in the national GDP of Bangladesh despite having potentiality in these sectors in the coastal region of Bangladesh. According to the department of statistics in the University of Chittagong, about 15% of the road accidents in 2017 occurred in the Barisal and Khulna divisions. This research aims to assess the risk associated with the adjacent points of the national highways for a proposed road alignment to be built in the country's coastal region connecting with the mainland. This study conducts the Corridor Selection Matrix to select the best roadway alignment and a semiquantitative approach to analyze the effect of different factors for road accidents in the National Highway-1 (N1) at the Chittagong district. Analyzing the existing road traffic condition by field visit, International Road Assessment Program (iRAP) and Global Information System (GIS) most risky areas found for different exposure conditions, locality and pedestrian characteristics will be determined. This research will help to understand the road accident severity and its pattern in Chittagong with the growing number of development i.e. tourism in particular and make a proper safety framework to prevent road accidents in the country by better understanding the related factors.

Armana Sabiha Huq

Maintenance Strategies - 1

Improving Pavement Condition at an Accelerated Pace: The City of Phoenix Accelerated Pavement Maintenance Program

In 2018, the Phoenix City Council took action to increase resources available to triple the amount of major street rehabilitation across the City. This two hundred-million-dollar advance sought to quickly and dramatically improve the pavement condition of the City’s major streets through a five-year resurfacing program. With more than 4,850 miles of publicly maintained streets in the City, the Accelerated Pavement Maintenance Program (APMP) project has significant positive impact on Phoenix residents, businesses, and visitors as people travel throughout the City. The Street Transportation Department’s APMP team worked hard to deliver outstanding results for the community in a short timeframe through hard work, rigorous analysis, collaboration, and innovative thinking. To accelerate the existing five-year plan into a three year timeframe and add additional projects, the team increased communication and coordination with stakeholders, both internal and external, to avoid pavement cuts, engaged in a major public outreach and involvement campaign using innovative approaches, partnered with paving contractors and industry, and used an analysis of pavement condition to identify and prioritize projects using the principles of asset management. The APMP progressed ahead of schedule, delivering approximately eighty percent of the programmed miles within the first three years. In the last three years, the APMP has completed the rehabilitation of nearly eleven percent of the entire street network, more than ever before. After completing several years of increased maintenance activity, the City is taking steps to protect this investment by improving the ongoing maintenance and preservation of City streets.

Ryan Stevens
Smart Infrastructure Asset Management System on Metropolitan Expressway in Japan

The enormous aging road infrastructure is serious present issue in Japan. This critical problem is caused by the rapid increase of deterioration and lack of engineers due to the population decline. In order to deal with this problem, we need an innovative approach for the improvement of productivity in road asset management as soon as possible. This innovative system should accurately predict the diagnosis and deterioration of the road structure with the improving the efficiency and rationalization of inspection technique, which then enables timely and appropriate repair and reinforcement.Metropolitan Express Company Limited, which is an expressway administrator in Tokyo Japan, utilizes smart infrastructure management system that supports to optimize life cycle cost and realize sustainable infrastructure. This innovative system makes use of ICT (Information and Communication Technology), and connects various information efficiently by using IoT (Internet of Things). Furthermore, it can allow to visualize prospective tasks and to help judgement of engineers by applying AI (Artificial Intelligence) technology.In this paper, the outline of asset management system applied in Metropolitan Expressway Company for our maintenance work is introduced. As core technologies of this asset management system, data platform based on GIS (Geographical Information System), the utilization of digital twin by means of 3 dimensional point cloud data, and patrolling and inspection system that makes use of the patrol vehicle with high performance drive recorder are mainly described.

Hirotaka Nakashima, Taishi Nakamura, Yusuke Hosoi, Koji Konno, Hinari Kawamura

Decarbonizing Road Transport

Evaluation of the CO2 Reduction Effect of Low Rolling Resistance Asphalt Pavement Using the Fuel Consumption Simulation Method

This study verified the CO2 emission reduction effect of the Low Rolling Resistance Asphalt Pavement (LRRAP) using the fuel consumption simulation method for evaluating the automobile consumption rate. In this verification, the relationship between the rolling resistance coefficient reduction ratio and CO2 emission reduction ratio was first studied for two types of vehicles: heavy duty vehicles and light duty vehicles. Subsequently, the CO2 reduction was evaluated when applying LRRAP to expressways and major roads across Japan. The CO2 emission reduction effect of the difference in traffic volume was also studied. The study indicated that the reduction effect of applying LRRAP corresponds to approximately 1.1% for the entire transportation sector in Japan. Also, since the routes with a larger traffic volume indicated a larger application effect, it clarified that CO2 can be efficiently reduced by prioritizing route maintenance with a larger traffic volume.

Yu Shirai, Atsushi Kawakami, Masaru Terada, Kenji Himeno
Green Energy Sources Based on Thermo-Electrochemical Cells for Electricity Generating from Transport, Engineering Buildings and Environment Waste Heat

Harvesting of low-grade waste heat and conversion it into electricity is a promising strategy for increasing the efficiency of various engineering systems in road construction and of renewable energy development direction. Thermo-electrochemical cells can directly convert low-grade thermal energy (Temperature of heat sources lower than 150 ℃) into electricity without contamination of the environment and consuming any materials. The new type of electrode material based on nickel hollow microspheres has been presented in this work. It was demonstrated, that nickel hollow microspheres-based thermo-electrochemical cells can provide the highest Seebeck coefficient for aqueous electrolytes-based thermo-cells. The results of the investigation of the composition and structure of nickel hollow microspheres-based electrodes are presented in the work. Because of the low cost of nickel microspheres, developed thermocells may become commercially viable for harvesting low-grade thermal energy. It is supposed that the effect obtained with Ni electrodes characterized with well-developed surface area allows producing the commercial thermo-electrochemical cells for waste heat harvesting.

Igor N. Burmistrov, Nikolay V. Kiselev, Elena A. Boychenko, Nikolay V. Gorshkov, Evgeny A. Kolesnikov, Stanislav L. Mamulat

Long Term Pavement and Asset Performance - 2

An Approach to Estimate Pavement’s Friction Correlation Between PCI, IRI & Skid Number

Friction in pavements is an especial phenomenon that varies upon many variables such as weather, pavement’s age, material properties, and tire-surface contact. Furthermore, it is a very important factor since it is related to safety. To measure friction there are different procedures and methodologies. Depending on the method, and even the equipment used to measure skid resistance, output data can vary. In addition, friction varies with time. Some studies state that friction has a decreasing linear behavior, and others say behavior dependents on temperature and the level of exposure of aggregates’ surface, so friction in pavements is a subject still on development and having consistent measurements of skid resistance is complicated. Based on the Long-Term Pavement Performance (LTPP) data base, this study found that friction can be related to the pavement condition index (PCI) and roughness (IRI). These findings can support alternative approaches to estimate skid resistance on a more suitable way and take proactive actions to maintain adequate safety ranges on roads.

Carlos J. Obando, Jose R. Medina, Kamil E. Kaloush
Effect of Different Aggregate Gradations on Rutting Performance of Asphalt Mixtures for UAE Roadways

Rutting or Permanent deformation is one of the primary distresses that occur in asphalt pavements. Many researchers showed that about 55 to 80% of rutting occurred in the surface layer of asphalt pavement. Since this layer contains 90–95% aggregates by weight, studying the properties of the aggregate component becomes very crucial. Gradation is one of the important characteristics of the aggregates affecting the performance of hot-mix asphalt (HMA) particularly against rutting. The skeleton of the internal aggregate structure is highly affected by gradation, which directly impacts the rutting resistance of the asphalt mixture. The main objectives of this research study are to evaluate the effect of aggregate gradation type including GAP-graded, FHWA gradation, UAE gradation, and gradation by Bailey method on the rutting performance of HMA for the UAE’s hot climate. A total of 48 Superpave gyratory-compacted specimens of different aggregate gradations were prepared and tested in the mixture design stage to determine the design asphalt binder content for each mixture/gradation type. Another set of Superpave gyratory-compacted (SGC) specimens were also prepared using the design asphalt binder content obtained for each asphalt mixture/gradation for the performance testing phase. The test results and analysis provided a full picture of the performance and behavior of asphalt mixtures using different aggregate gradations. The results shows that the GAP and the Bailey gradations have the highest rutting resistance in both Dynamic modulus and flow number tests.

Khalil Almbaidheen, Ghazi Al-Khateeb, Waleed Ziada, Myasar Abulkhair
Evaluation of AASHTO Mechanistic Empirical Design Guide Inputs to the Performance of Tennessee Pavements

Tennessee Department of Transportation (TDOT) is among the States Departments of Transportation, taking measures to implement the Pavement Mechanistic-Empirical Design (PMED) approach and analysis from the AASHTO 1993 pavement design procedure. TDOT has funded the calibration of Tennessee distress models and traffic inputs for its interstate and state routes. In this study, local and national calibrated models are used to evaluate the performance of Long-Term Pavement Performance (LTPP) sites in Tennessee using AASHTOWare Pavement Mechanistic-Empirical Design v2.5.5 (PMED v2.5.5). Traffic inputs include level 1, LTPP traffic volume adjustment factors; level 2, Tennessee statewide traffic volume adjustment factors; and level 3 the default national traffic volume adjustment factors. The study also considers LTPP sites that are relatively close to climatic stations, Modern Era Retrospective-analysis for Research and Application (MERRA) and North American Regional Reanalysis (NARR), in distance and elevation. The distances and elevation differences were considered to eliminate the need for creating visual weather stations. The statistical analysis comparing measured and predicted distresses showed that local calibrated distress models with level 2 traffic inputs predicted relatively close to the measured distresses compared to traffic levels 1 and 3. For all traffic levels and local calibration, MERRA predicted better on bottom up cracking and permanent deformation, while NARR predicted better on terminal IRI. For national calibrations, MERRA predicted better on bottom up cracking, Jointed Plain Concrete Pavement (JPCP) transverse cracking, and total transverse cracking, while NARR predicted better on permanent deformation and terminal IRI.

Onyango Mbakisya, Msechu Kelvin, Udeh Sampson, Owino Joseph
Influence of Dynamic Analysis on Estimation of Rutting Performance Using the Fixed Vehicle Approach

Vehicles traversing on asphalt pavements are of diverse types comprising different axle configurations. Globally, the flexible pavement design guidelines are based on fixed vehicle approach and the pavement analysis is carried out by adopting static or quasi-static loads ascribed to the lack of provision for dynamic load representation and intricacies in the analyses. However, it has been found that the dynamic component significantly contributes to the time-varying nature of vehicular loads that affects the asphalt pavement performance. On this note, this paper focused on estimating the rutting performance of asphalt pavements under the influence of dynamic vehicular loads. The dynamic analysis was performed on a pavement system modeled in ABAQUS® software by considering traffic loads due to four vehicle types with different axle configurations. The surface wearing course was represented by the power-law creep model to account for viscoelastic nature of the asphalt. The time-varying loads were represented by a lumped parameter model for the vehicle accounting for the inertia, stiffness, and damping characteristics in addition to the self-weight. Further, the vertical strains obtained from the dynamic analysis were compared with the estimates of static analysis, thereby, examining the differences in the strain ratios responsible for rutting failure due to the two analyses. Additionally, calibration factors for strain ratios were proposed, which will exemplify the realistic contribution of dynamic loads in rutting performance estimation. Thus, this study will help advance the existing pavement design framework through the incorporation of the vehicle dynamics effects in rational asphalt pavement performance evaluation.

Gauri R. Mahajan, Radhika Bayya, Krishna Prapoorna Biligiri

Street and Highway Designs for CAVs - 1

A Review on Benefits and Security Concerns for Self Driving Vehicles

Self-driving vehicle technologies are receiving attention and there is a promising trend in market for future development. Based on their advanced features, self-driving vehicles are expected to increase the mobility for those with disabilities, reduce the amount and severity of accidents, enhance the utility of time on travel and reduce the air pollution. On the other hand, this technology brings safety and security challenges, which need to be addressed before their mass implementation in roads. The purpose of this study is to discuss the advantages and disadvantages of autonomous vehicle technology through providing comparative analysis. This paper also presents an overview of recent research on self-driving vehicle safety issues and the shortcomings of this technology in a broader sense. As a result of the study, suggestions about the future of self-driving vehicle will be provided for planners and policy-makers.

Gozde Bakioglu, Ali Osman Atahan
Contrast Ratio of Road Markings in Poland - Evaluation for Machine Vision Applications Based on Naturalistic Driving Study

Road markings are critical road safety features for both human drivers and for machine vision technology used in advanced driver assistance systems and in the emerging technology of automated vehicles. Amongst the parameters, contrast ratio is necessary for appropriate recognition of road markings. To assess the contrast ratio of road markings at various roads, still images of roadway were obtained from a dashboard camcorder used for a naturalistic driving study in Poland. Road markings and neighbouring roadway surface were measured for luminance and Weber contrast was calculated. At the studied representative roads average contrast ratio was 0.8 under daytime illumination and 2.0 at night; enhancement of the contrast through digital image manipulation resulted in increases to 2.3 and 6.8, respectively. Under poor visibility daytime conditions (interference from glare or rain), average contrast ratio dropped to 0.5 (enhanced 1.4); in the worst case it was below 0.1. Consequently, the current machine vision technology could fail under some poor visibility circumstances. The image enhancement indicated that both the initial and digitally enhanced contrast ratios were important.

Tomasz E. Burghardt, Anton Pashkevich
San Diego Bus Rapid Transit Using Connected and Autonomous Vehicle Technology

Parsons has been contracted by the San Diego Association of Governments to deliver an innovative pilot demonstration of Bus-On-Shoulder (BOS) operations on a limited access freeway using state-of-the-art technology for driver assistance. Through the deployment of Vehicle to Infrastructure Connected Vehicle (V2I CV), Lane Departure Warning (LDW), Blind Spot Warning (BSW), and Forward Collision Warning (FCW) technologies, this BOS pilot project will demonstrate that bus performance can be improved by allowing buses to drive on the freeway transit-only shoulder lane with minimal changes to the roadway. The pilot project will extend along Interstate 805 (I-805) from Chula Vista/South Bay to State Route 94 (SR 94) into downtown San Diego in both directions of travel. Upon completion of the pilot, all improvements to the freeway that were installed for the purposes of this pilot project will be removed.Parsons is developing, integrating, and providing the following technology for this project: LDW system alerting bus drivers that they are drifting into adjacent lanes. BSW system alerting bus drivers of bus blind spots. FCW system alerting bus drivers of forward obstructions. Ramp metering Transit Signal Priority system holding vehicles at the ramps, as well as displaying. messages on Changeable Messages Signs at the ramps warning drivers of the buses

Dan Lukasik, Dmitri Khijniak

Maintenance Strategies - 2

Introduction to the RoadMark System Low Cost, Fast and Flexible Data Collection for Rural Roads

Rural roads are often the poor cousins in the road sub-sector, despite comprising the majority of the public road network, representing a considerable public investment. They have a profound impact on the quality of life for the significant rural population and economy; and directly impact urban citizens too, influencing the availability and price of many basic commodities. Rural roads have important economic, social, political, environmental and equity consequences that no successful country can ignore.However, attracting and retaining the quality of professional staff required is challenging and funding is frequently woefully inadequate, exacerbated by weak planning due to inadequate data about these rural road assets.Based on projects undertaken in Myanmar from 2016 and in Cambodia in 2018–9, the RoadMark system was developed to address the shortcomings common in managing rural roads, which were inadequately addressed by other existing systems. RoadMark provides: The ability to capture basic inventory and condition data for all the key types of road assets, using only a GPS- enabled Smartphones, thereby avoiding the requirement for specialised and expensive equipment and its ongoing servicing; Fast survey speeds (important for large rural networks); Minimal training, (avoiding reliance on specialised or expensive experts); No requirement for any network referencing system to be established beforehand; Ability to monitor surveys remotely; Surveys that require no internet or mobile signals, (often problematical in rural areas); Ability to map flexibly, all road assets; Permanent availability of data and use in other applications; Cost-effective, inexpensive and flexible licensing options.

Mark J. Thriscutt
Similarity Between an Optimal Budget in Pavement Management & an Equilibrium Quantity of Demand-Supply Analysis in Economics

The Department of Highways (DOH) is a state agency under the Ministry of Transport, Thailand. The DOH has developed a pavement management system called the Thailand Pavement Management System where the International Roughness Index (IRI) is a serviceability measure index for highway maintenance performance evaluation. The DOH sets the thresholds of IRI at 3.50 m/km for the regular highway network with Annual Average Daily Traffic (AADT) less than 8,000 and at 3.00 m/km for the major trunk highway network with AADT of 8000 or above. Contrary to the traditional approach that specifies the output state, for instance the average IRI, of the network and then back-calculates the required budget to attain that state, this study presents a new method based on the so-called cost-benefit analysis of economics that optimizes both the required budget and the output state of the highway network to achieve the maximum net benefit of highway maintenance. The optimal budget is shown to have similar characteristics to the equilibrium quantity of goods of demand-supply analysis in economics. This study also proposes a new model to optimally allocate maintenance budgets between two highway networks to maximize the total net benefit for a given budget constraint. It is found that at the optimum the maintenance budget should be allocated in such a way that the marginal net benefit divided by the marginal cost should be constant for both networks. The proposed methodology has demonstrated itself to be a potential model for budget planning of the pavement management system.

Ponlathep Lertworawanich
Integrating Flexible Pavement Surface Macrotexture to Pavement Management System to Optimize Pavement Preservation Treatment Recommendation Strategy

Transportation agencies implement pavement preservation program to keep the good road in good condition for an extended period. This paper focuses on addressing pavement surface texture issues such as bleeding and raveling by investigating pavement surface macrotexture characteristics, developing surface macrotexture performance models for hot-mix dense graded overlay and chip seal, and establishing thresholds to trigger surface texture treatments. The surface texture evaluation of 20 pavement sections capturing nine (9) different types of pavement surfaces in the City of Phoenix were performed using automated and manual survey methods. Both FHWA Long-Term Pavement Performance (LTPP) and City of Phoenix pavement performance datasets were used for this study. Macrotexture is characterized by the surface texture between individual aggregates and thus is influenced by aggregates composition and binder type of the wearing course. A high macrotexture depth indicated by Mean Profile Depth (MPD) or Macrotexture Depth (MTD) represents a rough textured pavement surface. MPD above 1.2 mm exhibits a rougher pavement texture. The rate of change of MPD greater than 0.11 mm/yr. for thin hot-mix dense graded asphalt overlay and 0 mm/yr., for chip seal can be established as the raveling limits. The rate of change of MPD less than 0 mm/yr. for thin hot-mix dense graded asphalt overlay and 0.15 mm/yr., for chip seal can be established as the bleeding limits. Therefore, pavement macrotexture can be integrated to the pavement management system to optimize preservation treatment recommendation strategy.

Seng Hkawn N-Sang, Jose Medina, Kamil Kaloush

Safe Roads by Design - 2

MASH TL-3 Development and Evaluation of the Thrie-Beam Bullnose Attenuator

The thrie-beam bullnose system is a non-gating, redirective crash cushion that provides a safe, cost effective, non-proprietary option for shielding median piers and other median hazards. It consists of a guardrail envelope comprised of thrie-beam panels mounted at a height of 803 mm and supported by breakaway steel posts. The nose rail section and the first two adjacent rail sections are radiused and slotted, and the fourth and fifth rail sections are slotted. The combination of the radiused and slotted rail segments along with the breakaway posts allow the system to safely capture and decelerate vehicles impacting near the end or nose of the system, while redirecting vehicles impacting along the side. The barrier system was originally developed and evaluated under National Cooperative Highway Research Program (NCHRP) Report 350.In 2009, the American Association of State Highway and Transportation Officials (AASHTO) implemented an updated standard for the evaluation of roadside hardware. The new standard, the Manual for Assessing Safety Hardware (MASH), improved the criteria for evaluating roadside hardware beyond the previous NCHRP Report 350 standard through updates to test vehicles, test matrices, and impact conditions. A research effort was undertaken to evaluate the thrie-beam bullnose to MASH Test Level 3 through full-scale crash testing and modify the design as needed to meet the revised safety criteria. This paper details the evaluation of the thrie-beam bullnose through MASH TL-3 full-scale crash tests, modification of the original design to meet MASH criteria, and recommendations for implementation of the system.

Robert Bielenberg, Ron Faller, Cody Stolle
Safety Performance Evaluation of Modified Thrie-Beam Guardrail

Modified thrie-beam guardrail is a non-proprietary, longitudinal barrier system originally developed and evaluated under the National Cooperative Highway Research Program (NCHRP) Report 350 Test Level 3 (TL-3) and Test Level 4 (TL-4) safety performance criteria. Modified thrie-beam can be configured as both a single-sided roadside barrier and a dual-sided median barrier. The single-sided roadside configuration of the modified thrie-beam guardrail consists of 12-gauge thrie-beam panels mounted at a height of 864 mm and supported by 2,057-mm long W6 × 8.5 posts and W14 × 22 blockouts with an angled cutout in the web. The dual-sided modified thrie-beam guardrail is largely identical to the single-sided configuration, except that the blockouts and thrie-beam guardrail panels are mirrored on the backside of the system. Modified thrie-beam guardrail provides for increased vehicle capture and reduced deflection as compared to typical W-beam guardrails.In 2009, the American Association of State Highway and Transportation Officials (AASHTO) implemented an updated standard for the evaluation of roadside hardware. The new standard, the Manual for Assessing Safety Hardware (MASH), improved the criteria for evaluating roadside hardware beyond the previous NCHRP Report No. 350 standard through updates to test vehicles, test matrices, and impact conditions. A research effort was undertaken to evaluate the both the single-sided and dual-sided median barrier configurations of modified thrie-beam guardrail to MASH Test Level 3 through full-scale crash testing. This paper details the performance evaluation of the thrie-beam guardrail through MASH TL-3 full-scale crash tests and recommendations for implementation of the system.

Robert Bielenberg, Ron Faller, Karla Lechtenberg
In-Service Performance Evaluation of Iowa’s Sloped End Treatments

Sloped end treatments (SETs) were historically developed as low-cost, low-maintenance end treatments for rigid features like concrete barriers and bridge rails. Crash testing indicated that sloped end treatments are associated with significant instability for impacting vehicles, but their historical crash performance was not known.An in-service performance evaluation (ISPE) was performed to evaluate vehicle crashes with sloped end treatments in Iowa between 2008 and 2017. Researchers generated a geographic inventory of 658 sloped end treatment locations, reviewed crash narratives and scene diagrams for crashes near these sloped end treatments, and calculated an estimated crash rate and crash cost for these sloped end treatments. A total of 30 SET-related crashes were identified, resulting in one fatal crash and one severe injury crash. Eighteen of these crashes climbed the SET feature and seven crashes were associated with vehicle rollover, with eight unknown crash outcomes.The estimated sloped end treatment average crash cost was approximately $178,260. For comparison, crash costs for other fixed objects in the same vicinity as sloped end treatments, typically associated with roads with higher speed limits, averaged $67,449 per crash. Benefit cost was calculated for replacing select groups of sloped end treatments with various crash cushions. Nineteen of the crashes occurred on a total of seven bridges, indicating most impacts were in “black spot” locations. Researchers recommended prioritization of removal and replacement of some sloped end treatments based on crash history.

Cody Stolle, Jessica Lingenfelter, Khyle Clute, Robert Bielenberg
A Synthesis of 787-mm Tall, Non-proprietary, Strong-Post, W-beam Guardrail Systems

Since its development in the early 2000’s, 787-mm tall W-beam guardrail, commonly referred to as the Midwest Guardrail System (MGS), has proven to be one of the most versatile and robust roadside barrier systems in use today. The MGS has been designed and successfully crash tested in a wide range of configurations including both roadside and median systems, steel and wood post systems, blocked out and non-blocked systems, and variable post spacing systems. The MGS has also been successfully crash tested adjacent to steep roadside slopes, with an omitted post, in combination with curbs, and in special applications such as culvert mounted installations. Since the MGS is a non-proprietary barrier system, these various configurations can be used by roadway agencies all around the world.This paper contains details and drawings encompassing a wide range of 787-mm tall W-beam guardrail configurations that have been developed and evaluated to the safety standards of the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH). The various configurations are discussed in terms of key components and performance characteristics, such as test level and working width. Finally, implementation guidance is provided for the proper selection, layout, and installation of the various MGS configurations.

Scott Rosenbaugh, Robert Bielenberg, Ronald Faller
A Synthesis of MASH Crashworthy, Non-proprietary, Weak-Post, W-beam Guardrail Systems

Since its development in the early 2000’s, 787-mm tall W-beam guardrail, commonly referred to as the Midwest Guardrail System (MGS), has proven to be one of the most versatile and robust roadside barrier systems in use today. The MGS is typically configured as a strong-post system utilizing either W6 × 8.5 steel posts or 152 mm × 203 mm wood posts. However, multiple weak-post MGS configurations have been developed using S3 × 5.7 steel posts. These weak-post systems absorb energy through post bending instead of post rotation through soil, so they are favored in various special applications such as bridge rails, culvert mounted systems, and placement within pavements or mow strips. These weak-post guardrail systems are non-proprietary and can be used by roadway agencies all around the world.This paper contains details and drawings encompassing various weak-post MGS configurations that have been developed and evaluated to the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH) safety standards. The systems are discussed in terms of key components and performance characteristics, such as test level and working width. Finally, implementation guidance is provided for the proper layout and installation of the weak-post MGS configurations.

Scott Rosenbaugh, Robert Bielenberg, Ronald Faller
The Safety Highway Geometry Based on Unbalanced Centripetal Acceleration

Road accidents take a significant part in the human lives losses and financial resources in worldwide sense. In order to devise new strategies to combat this problem there is a continuous search for new approaches from researchers, dealers and government agencies. Recent changes in the Brazilian traffic code, such as the increase of the score limit on the driver qualification and the restrictions on speed enforcement, imposed a new operational scenario. Speeding should increase and, consequently, reflecting more accidents and severity. A proposed model in this work has several equations, correlating road geometry parameters and accident record indexes. This model can be applied as an objective policy tool of physical improvements and speed reduction focusing on accident severity and amount. It was taken the unbalanced centripetal acceleration on horizontal curves as the main derived term, generated mainly by excess of speed in relation to the allowed one, under the Physics and human restrictions criteria. There were selected some Brazilian road segments to apply this model, conceiving specific equations and evaluating confidence under determination coefficient, that resulted a good level to the selected place.

Creso de Franco Peixoto, Maria Teresa Françoso
Stiffening Guidance for Temporary Concrete Barrier Systems in Work Zone and Construction Situations

Portable concrete barrier (PCB) systems are utilized in many situations, including placement adjacent to vertical drop-offs, work zones, and construction areas. Free-standing PCB systems are known to have relatively large deflections when impacted, which may be undesirable when dealing with limited space behind the barrier, such as on a bridge deck or with limited lane width in front of the barrier system. The risk of injury to workers in the work zone or construction area from displaced PCB systems is great. In order to allow PCB systems to be used in space-restricted locations, a variety of PCB stiffening options have been used, including beam stiffening and bolting or pinning the barriers to the pavement. This research evaluated the safety performance of the New Jersey Department of Transportation (NJDOT) PCB, Type 4 in various stiffening configurations according to the Test Level 3 (TL-3) criteria set forth in MASH 2016. All tested configurations successfully met all the requirements of MASH 2016 test designation no. 3–11 which was a 2,270-kg pickup truck impacting at a speed of 100 km/hr and $$25^\circ$$ 25 ∘ . This research further reviewed and correlated stiffening techniques to dynamic deflection and working widths, as well as barrier segment damage. Implementation guidance is provided for the various PCB stiffening options to help protect the workers in work zone and construction areas.

Karla Lechtenberg, Chen Fang, Ronald Faller
Safety Performance Evaluation of a Non-proprietary Type III Barricade for Use in Work Zones

Work-zone traffic control devices, such as Type III barricades, must satisfy impact safety standards to improve safety and minimize risk for the motoring public traveling within work zones and on our highways and roadways. More specifically, this study focused on developing improved methods and products for addressing safety and mobility in work zones by evaluating new technologies and methods, thereby enhancing the safety and efficiency of traffic operations and highway workers. The non-proprietary, Type III barricade had three horizontal High-Density Polyethylene (HDPE) panels with a 1,219-mm × 762-mm × 2-mm aluminum sign attached to the top two barricade panels. The barricade panels were attached to two Perforated Square Steel Tubing (PSST) uprights, which were inserted into two PSST vertical stubs welded to two PSST legs. All PSST was galvanized ASTM 1011 Grade 55 steel. A 22.7-kg sandbag was placed on top of the end of each leg. A Type A/C warning light was attached to the front of the top barricade panel and upright at both upright locations. All of the impacts on the non-proprietary Type III barricade systems resulted in acceptable safety performance according to MASH 2016. Since the system is non-proprietary, any manufacturer could provide the components as long as they had similar dimensions and material grade as the as-tested system. It is anticipated that the Type III barricade without an attached aluminum sign panel would perform equivalent to or better than the system tested with a sign panel.

Karla Lechtenberg, Ronald Faller, Jennifer Rasmussen, Mojdeh Asadollahi Pajouh

ITS Design and Implementation Strategies

Unified ITS Environment in the Republic of Tatarstan

The Republic of Tatarstan has always been a pioneer among other regions of Russia in the development of innovative and digital technologies. Tatarstan is changing and adapting to be relevant in healthcare, economy, and transport areas. Challenges of modern transport systems cannot be solved with strategies and tools from the past. Intelligent transport systems (ITS) are being actively introduced to overcome the challenges of modern life. The article describes the development of ITS in the Republic of Tatarstan. There are considered issues related to existing technologies, priority areas of development, and the implementation of a unified ITS environment. Much attention is paid to the ITS subsystems, which are being developed in order to ensure the safety and comfort of the residents of the Republic.

Rifkat Minnikhanov, Maria Dagaeva, Sofya Kildeeva, Alisa Makhmutova

Road Pricing and Tolling

Assessment of the Potential Implementation of High-Occupancy Toll Lanes on the Major Freeways in the United Arab Emirates

The High Occupancy Toll (HOT) lanes would provide a great opportunity for enhancing the transportation sector through potential reduction of roadway congestions, reducing the overall sector costs, and mitigating the carbon footprint. Based on the literature review, HOT lanes system is expected to provide a great opportunity to enhance the transportation sector through potential reduction of roadway congestions, reducing the overall sector costs, and mitigating the carbon footprint resulting from this sector. In this study, a micro-simulation was conducted using VISSIM software on a selected segment of a major freeway. The results indicated that the HOT lanes could reduce the delay time and overall travel time by around 19.02 and 23.44%, respectively, while the average travel speed could increase by up to 24.98%. Additionally, it was found that HOT lanes can significantly reduce the fuel consumption by around 12.7% and that resulted in air emissions reduction by 19.9 and 15.9% for the CO and the NOx, respectively.

Ahmed Shabib, Mahmoud Khalil, Muamer Abuzwidah

Driver Behavior Strategies

Posted Road Speed Limits in Abu Dhabi: Are They Too High? Should They Have Been Raised? Evidence Based Answers

Road posted speed limits (PSL) in Abu Dhabi (AD) were raised in mid-2018. Before raising PSL by 20 kph, AD drivers were legally allowed to drive 20 kph above PSL. Thus, there was a speed buffer within which drivers would not be fined for speeding. While it has been stated (through public media) that the elimination of this speed buffer would increase safety, this paper challenges this view. This paper describes how the argument for increased safety through increased PSL quickly breaks down. The paper bases its arguments mainly on basic physics, as well as local research data and findings. More specifically, this paper not only shows how existing road design may not safely accommodate raised PSLs (or even previously lower PSLs), but also how fatal road injuries are more likely to occur on AD roads with higher design speeds. The paper also describes how increased PSL may increase the potential for liability and greenhouse gas emissions. This paper concludes that while speed buffers should have been removed, PSL should not have been increased since higher PSL may negatively affect road safety while decreasing travel times only marginally. That is, there is not much to gain from raising PSLs, but there is potentially a lot to lose. Thus, the author urges policy makers to make decisions based on science and solid evidence. This is relevant as decisions such as increasing PSL on public roads may have a significant negative impact on public health through increased injury/mortality rates and pollution levels.

Francisco Daniel B. Albuquerque

Transport Responses to the Pandemic

The Impact of the COVID-19 Pandemic on Mobility Behavior in Istanbul After One Year of Pandemic

Worldwide, the COVID‐19 pandemic has resulted in significant changes in activity patterns and travel behavior. Some of these changes are due to responses to governmental or personal measures for controlling the spread of the pandemic (e.g. partial lockdowns, remote education, or work). This paper examines changes in human mobility over 1 year period (from March 1st, 2020 to March 30th, 2020) in Istanbul, Turkey, a megacity in developing countries. The study period imposed three distinct waves, 1st wave (March-April), the second wave (Nov/202–Jan/2021), and 3rd wave (March/2021-still continue). The paper includes two parts. The first part is an analytical analysis for traveler mobility trends using data of public transit automatic fare collection system and traffic volume counting sensors along with Istanbul metropolitan. For the 1st wave, mobility changes have a V-shape trend for public transit riders and a smooth U-shape for reported vehicles by highway sensors. Despite the severity level of the COVID-19 pandemic and mobility restriction measures during 2nd wave, there was a smooth drop in mobility indicating a change in human reaction toward pandemic severity. The second part is investigating differences in individuals’ trip characteristics for before the COVID-19 pandemic and after one year of pandemic based on data collected from an online survey. Tends to shift to use personal vehicle for daily trips, indicate more effective decisions should be implemented next to staggered working hours and reductions transit capacity to encourage travelers for using the sustainable transportation system.

Ali Atahan, Lina Alhelo
The Evaluation of the Impacts on Traffic of the Countermeasures on Pandemic in Istanbul

Governments have taken various countermeasures to slow down the effect of the Covid-19 virus, which has affected the whole world since the beginning of 2020. This study aims to evaluate the impacts of the countermeasures taken by the government on travel behavior in Istanbul, Turkey, through a large-scale survey (approx. 150.000 respondents), remote traffic microwave sensor (RTMS) and transit system electronic toll collection (ECT) data. The countermeasures have been taken by the governments were all day on weekends and between 9 pm and 5 am on weekdays, closure of the restaurants, cafes except take away, stepwise working hour measure and determination of the working hour between 10 am and 4 pm. The survey was developed to allow electronic surveys to be designed on a word processor, sent to, and conducted on standard entry level mobile phones. As a result of the survey, it is estimated that there is a 9% increase in the use of private vehicles, and the road traffic congestion is expected to be increased accordingly. Despite the stepwise working hour measure of the government, the morning and evening peak hours of the traffic did not change. Also, the number of vehicles before and during the pandemic passing through the Bosporus via two bridges which connect the two continents and are the main transportation corridor of Istanbul, is analyzed. According to the November, 2020 data, the number of the vehicles has decreased by almost 14% on weekdays in comparison with the data of November, 2019 for both bridges.

Mahmut Esad Ergin, Halit Ozen, Mustafa Ilıcalı

New Approaches to Performance Delivery

From Reactive to Proactive Maintenance in Road Asset Management

In road asset management, reactive pavement maintenance is still used in most countries. In this policy, corrective measures are only initiated after clear pavement distress or other deficiencies in road condition have been identified. However, in the philosophy of proactive maintenance, the root causes of damages are always determined before making any corrective measures. In addition, any measures chosen, focus on eliminating or reducing the causes of the problems. The central theme of proactive maintenance is to extend the service life of pavement in accordance with the following principles: 1) the avoidance of unnecessary repairs, 2) damage must never become an acceptable “normal,” and 3) approaching damage is monitored and responded to in a timely manner.In Finland, a pilot towards proactive asset management started in 2015, in cooperation between The Finnish Transport Infrastructure Agency and Roadscanners. The goal of the pilot was to develop and test new innovative methods to improve the productivity of paved roads maintenance. A further aim was to provide new information on the life cycle costs of various roads and the factors that increase these costs.The results of piloting have been promising. The weakest links increasing asset management costs have been identified and maintenance measures addressing the real root causes of the problems have been implemented. As a result, calculated annual paving costs have been reduced already by 20–40%. In addition, valuable information has been collected of the LCC of different maintenance measures. This information is used when moving towards more proactive maintenance policies.

Timo Saarenketo, Vesa Männistö
Observing How Influence of Nature Phenomena Against Inside Tunnel by Air Pressure Information

Monitoring inside the tunnel is important to be safe for road. A long mountain tunnel such as Kan-Etsu tunnel must ventilate the road. Ventilation system for Kan-Etsu tunnel controls the rotation speed of fans installed inside the tunnel to fill the lack of wind volume for ventilation. However, the fans cannot change rotation speed abruptly. Therefore, the ventilation system estimates near future conditions and calculates the necessary rotation speed. The ventilation is influenced by winds which are generated by traffic cars and nature phenomena, so that its estimation needs to recognize cars and nature effecting. Although the existing system measures traffic influence with a traffic counter installed in front of the tunnel, the system cannot measure natural phenomena. In addition, installed wind sensor in the entrance measures wind speed. The measured speed is treated as a ventilation result, but natural wind cannot be extracted from the sensor result. Therefore, the influence from nature wind haven’t been clear. To measure the influence is important to improve the ventilation controlling in the tunnel. In this paper, we reported influences of natural phenomena against inside tunnel conditions by monitoring air pressure. By observing pressure movement at each entrance, nature effecting can be measured. In this paper, pressure sensor arrays were installed at entrances and inside roads. By observing sensor behaviors, tunnel condition was monitored. The observation was executed multiple times but different seasons. As a result, this paper showed natural wind from each entrance influences the tunnel inside condition.

Kensaku Kawauchi, Yumi Watanabe, Yuichi Mizushima, Takeo Hosokai
Road Asset Management: Innovative Approaches

Maintenance and management of road assets is a crucial factor when it comes to making strategic decisions aimed at achieving optimal and sustainable conservation of the network. While it is widely acknowledged that digitalization and smart data analysis of different processes is on the rise, the Road asset management field is no stranger to this matter. As a case in point of the latter, some of the latest innovations include the collection of real time data using smart sensors, intended to optimize the management of asset’s risk of failure. This type of innovative approaches has proved to be highly effective when implemented in the Federal Roads Network of the United Arab Emirates, where real time data of traffic, flood monitoring systems, and environmental parameters are being constantly collected.Under the project “Supply of technical assistance in the Civil Engineering field for the Assets and Roads Management Systems” and the consultancy services of the Spanish company Rauros Management Consultants, several smart sensors have been installed in strategic and critical locations in order to analyze the evolution of the parameters and ultimately, serve as a baseline for decisions to be made based on the immediate risks and conditions the Road Network may face. Following a strict communication protocol and data synchronization with the expert management system ICARO (developed by Rauros), the Ministry of Energy and Infrastructure has achieved an exceptional level of standards, ranking in the highest positions worldwide in Road Asset Management development and innovation.

Soughah Salem Al-Samahi, Fernando Varela Soto

Traffic Planning and Forecasting – 2

Evaluating the Efficiency of Constructability Review Meetings for Highway Department Projects

Constructability review (CR) meetings are held before the completion of the project design to define potential site conflicts; reduce design errors, delays, and cost overruns; and improve construction site safety. The main objective of this research is to assess current practices associated with conducting CR meetings and provide specific guidelines that increase CR meeting efficiency. The research methodology included evaluating current CR meeting practices by different state DOTs and conducting interviews with multiple construction project stakeholders to assess different parameters affecting CR meeting success. The research findings showed that CR meetings should be scheduled at 60% to 70% of design completion. At least 3 contractors should be included, and a formal checklist of items should be provided by the constructability review manager for discussion throughout the meeting. Successful CR meetings result in reduced site conflicts, cost overruns, schedule delays, and they improve site safety.

Amin K. Akhnoukh, Minerva Bonilla, Nicolas Norboge, Daniel Findley, William Rasdorf, Clare Fullerton
A Novel Method for Aggregate Tour-Based Modeling with Empirical Evidence

The use of agent-based or activity-based model (ABM) is growing to overcome the limitations of traditional 4-step models. Aiming at capturing complex behaviours, over the last 30 years of development, ABM behaviour realism is still limited, let alone vast costs and poorness in application, especially for major schemes and government interventions. This paper presents a state-of-art tour-based mechanism in aggregation, based on Department for Transport UK advice and PTV Visum tour-based models. We address their limitations by presenting novel solutions, and mitigate the challenge in traffic forecasting by an alternative framework. Featured with ABM properties (considering the linkage of trip chains, variable activity durations, tour main/sub mode choice, tour main destination/intermediate-stop choice), the aggregate design focuses on demand-supply consistency, built-in realism, inherent sensitivities to transport policies. Complex tours with intermediate stops are considered, joint travel with parents escorting children to school and half-tours to external areas are approximated with assumptions. The aggregate tour framework is subject to rigorous tests on model system convergence, achieved by MSA feedbacks with overnight model runs. A gap function will be shown to measure the equilibrium status between demand and assignment models (small number of ABM feedbacks, typically fixed, prone to errors with sensitivity issues). Outturn elasticities for realism tests (fuel cost, parking cost, transit fare) will be shown in comparison to established values, and model sensitivity will be shown by transit fare strategy tests. A case study of Wuhan City will be shown as empirical evidence, carried out successfully funded by the World Bank.

Yanling Xiang, Shiying She, Meng Zheng, Heng Liu, Huanyu Lei
Multilayer Perceptron Modelling of Travelers Towards Park-and-Ride Service in Karachi

The imbalance between public and private transport causes congestion. Currently, congestion is due to individuals driving their automobiles to work in Karachi central business districts (CBDs). Therefore, the park and ride (P&R) service has been utilized widely in several countries as part of travel demand management (TDM). Consequently, P&R has proved successfully reduced congestion and difficulties to locate parking spots in the urban center. Travelers cannot be persuaded to adopt P&R without knowing their travel pattern. Accordingly, a travel behavioral survey was conducted, to eliminate imbalances between public and private mobility. Therefore, modal choice models were to identify the variables influencing the decision to accept P&R service of single-occupant vehicles (SOV). Data were collected by an adapted self-administered questionnaire through a survey approach. Mode choice models developed through multilayer perceptron (MLP) of artificial neural network (ANN) approach by using statistical package for the social sciences (SPSS) version 22. The research findings were more towards the socio-demographic factors. Furthermore, travel time, travel expenses, environmental protection, avoid mental stress, parking problem, vehicle sharing, and travel directly from home to office were found significant variables. In conclusion, the SOV users may be encouraged to move into P&R services by overcoming these influencing elements and balance push and pull measures of TDM. Thus, policymakers can benefit from study results and provide a base for future studies on sustainable modes of public transportation.

Irfan Ahmed Memon, Ubedullah Soomro, Sabeen Qureshi, Imtiaz Ahmed Chandio, Mir Aftab Hussain Talpur, Madzlan Napiah
Congestion on Canada’s Busiest Highway, 401 Problems, Causes, and Mitigation Strategies

The problem of congestion on highways is frustrating and reflects the inefficiency of the transportation network. Growing cities and economies have resulted in high population density regions across the Greater Toronto Area (GTA). The study area of this paper will be a worst-affected section on the Highway ON-401 which runs through dense residential communities from North York till Mississauga. There is a very major bottlenecking problem in the study area which results in very significant delays for commuters and reduces confidence in the transportation infrastructure across the province. To tackle this urban congestion, the Government of Canada has invested more than $8 billion in over 2,700 infrastructure projects across Ontario. The province of Ontario plans to invest more than $7.3 billion in public transit infrastructure over the next ten years (MTO, 2020). This paper aims to identify affected areas, causes, and potential solutions.

Abdul Basith Siddiqui

Multi-Stakeholder Transportation Strategies

A Holistic Approach for the Road Sector in Sub-Saharan Africa

The road sector is increasingly neglected in development aid. This is particularly visible in Sub-Saharan Africa where road networks are deteriorating rapidly, especially in rural regions, whilst basic connectivity to all-weather roads still lags behind other parts of the world. Major concerns expressed by donors relate to persistent maintenance problem, the associated decline in the value of investments, and the carbon footprint of road projects. Using a case study in Liberia, this paper will recall the value of effective transport linkages for rural regions as a necessary condition for substantial poverty reduction, while also proposing alternative means to develop them through governance reform, an increased role for the private sector, as well as new technical solutions such as the use of low-cost polymer-based roads and low-cost motorbike paths. Taken together, these instruments will give the rural population better access to roads, thus to markets, health and education facilities, and at the same time keep the carbon footprint significantly lower than with conventional technologies.

Tim Lukas Kornprobst, Ulrich Thüer, Yana Tumakova

Innovations in Road Materials

The Introduction of Micro - & Nanodispersed Fillers into the Bitumen Binders for the Effective Microwave Absorption (for the Road, Airfield & Bridge Pavements)

In this paper, the means of improving the efficiency of heating bituminous binders modified with micro- and nanodispersed fillers under the influence of microwave is described. The carbon nanomaterials (multi-walled carbon nanotubesis in particular) were selected upon the analytical review of the effectiveness of various electrically conductive and magnetically sensitive fillers in micro- and ultradispersed form to drive the efficiency of heating a bitumen binder in the microwave field.The experimental of the study included the preparation of a bitumen binder samples with the addition of electrically conductive and magnetically sensitive fillers, and specifically those selected on the basis of theoretical studies of multi-walled carbon nanotubes and various types of ferrite waste from metallurgy. The influence of modification of bitumen samples on the rate of their heating by electromagnetic microwave radiation is analyzed upon the obtained thermal heating coefficients. It is shown that the combination of small carbon nanotubes and magnetosusceptible waste additives provide the fastest and most uniform heating, and the optimal ratio of the components in the bitumen binder and mastic to ensure effective absorption of microwave energy coatings.

Stanislav Mamulat, Igor Burmistrov, Yuriy Mamulat, Dmitry Metlenkin, Svetlana Shekhovtsova
Rheological Properties of Rubber Modified Asphalt Binder in the UAE

In the 21st century, United Arab Emirates (UAE) is one of many countries that started focusing on building a sustainable eco-friendly system based on recycling waste materials rather than depositing them into landfills. Rubber generated from tires waste is one of those materials that have been proven to be a beneficial material in several applications especially in pavement engineering. This study aims at investigating the rheological properties and performance of Crumb Rubber-modified (CRM) asphalt binders that contain different crumb rubber contents by weight of the binder (5%, 10%, 15%, 20%, and 25%). The testing plan includes conventional tests, namely: penetration, softening point, and Rotational Viscosity (RV) tests and Superpave tests using Dynamic Shear Rheometer (DSR). Moreover, the AASHTOWare Pavement ME Design software was utilized to simulate the effect of using CRM asphalt binders on the pavement performance under local climatic conditions using two different pavement structures (thick and thin). Results showed that increasing the Crumb Rubber (CR) content increased the softening point, RV and rutting parameter (G*/Sinδ) significantly indicating an increased resistance to permanent deformation. The simulated pavement performance showed that modifying the binder with the CR in the thick and thin pavement structures has enhanced the pavement service life remarkably. The control asphalt binder failed due to rutting for thick and thin pavement structures at 12 years and 13 years, respectively. The modified asphalt binder with 25% CR content enhanced the pavement service life by up to 65% and 53% for thick and thin pavement structures, respectively.

Mohammed Ismail, Waleed A. Zeiada, Ghazi Al-Khateeb, Helal Ezzat
Recycling Waste Rubber Tires in Pervious Concrete Evaluation of Hydrological and Strength Characteristics

An alarming increase in the number of waste rubber tires (WRT) generated annually calls for the need to identify sustainable waste management practices as they pose serious threats to the quality-of-life. One such waste disposal strategy is recycling of WRT in pavement materials. Therefore, the objective of this research study was to investigate the effect of inclusion of WRT derived aggregates on properties of pervious concrete (PC). The size of recycled rubber aggregates (RA) varied from 4.75–2.36 mm, which were added to PC mix at 5 and 10% by weight of coarse aggregates; the new mix was called rubber-modified pervious concrete (RMPC). The porosity and permeability increased with increasing proportions of RA with reduction in the density and compressive strength. At 5% RA content; the magnitude of porosity and permeability increased by 6.9 and 53.1%, respectively, while the density and compressive strength reduced by 7.4 and 63.7%, respectively, compared to the control mix. Similarly, at 10% RA content; density and compressive strength decreased by 12.5 and 77.7%, respectively, while porosity and permeability increased by 15.2 and 63.4%, respectively, compared to the control mix. Owing to lower compressive strength (~5–8 MPa), RA as filler may be utilized in PC materials with non-vehicular traffic sections such as sidewalks and footpaths. Due to higher porosity and permeability, RMPC can help harness the stormwater benefits associated with PC, while simultaneously allowing for sustainable disposal of WRT.

Sahil Surehali, Avishreshth Singh, Krishna Prapoorna Biligiri
Incorporation of CFRP and GFRP Composite Wastes in Pervious Concrete Pavements

Over the past decade, utilization of carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) composites in aerospace, automotive, and wind energy sectors has led to generation of huge quantities of composite wastes (CW) at their end-of-life. This poses serious threat to environment and society, calling for identification of eco-friendly and cost-effective strategies to recycle CW into various applications. Therefore, the objective of this study was to recycle CFRP-CW and GFRP-CW in pervious concrete (PC) paving mixtures. The scope of the effort included addition of CFRP-CW and GFRP-CW into the PC mix at 0.33, 0.65, and 1% by volume to investigate their effects on hydrological and mechanical characteristics of the material. For GFRP-CW, porosity and permeability increased at the highest dosage by a magnitude of about 1 and 8.5%, respectively. However, for CFRP-CW, 1% increment in porosity was recorded at the lowest dosage, while permeability decreased by about 5–10% at all dosages. Furthermore, compressive strength increased by about 10–23% at all dosages of GFRP-CW, whereas it reduced by about 5% at lowest and highest dosages of CFRP-CW. Based on the test results, the optimum dosages for GFRP-CW and CFRP-CW were found to be 0.33 and 0.65%, respectively. Further, the properties of CW modified PC mixtures were within the general range for PC, reported in the literature. This study demonstrated that utilization of CFRP-CW and GFRP-CW in PC would serve as an environment-friendly and cost-effective strategy to recycle the CW in paving applications. Also, it is envisaged that this study will help formulate a framework for development of CW reinforced pavement materials from a sustainability perspective.

Akhil Charak, Avishreshth Singh, Krishna Prapoorna Biligiri, Venkataraman Pandurangan
Asphalt Modified with Recycled Waste Plastic in South Africa Encouraging Results of Trial Section Performance

The use of waste plastic is seen as a means of enhancing the visco-elastic behaviour of the binder used in hot-mixed asphalt, as well as providing significant environment benefits in reducing the quantity of plastic pollution. This initiative has drawn wide attention as it not only utilises recycled waste plastic but has been shown to improve the properties of the asphalt. The trials were constructed in two sections, one using a stone skeletal SMA mix type and the other a high modulus EME mix. The performance of the two trial sections was assessed on two occasions, a year apart, and included detailed visual assessments as well as assessments of riding quality, rut depth, and texture. The structural performance was also assessed using deflection based mechanistic analyses. Both trials have performed well to date under the large percentage of heavy vehicles transporting material to and from a nearby asphalt plant, rock quarry and Ready mix facility. It is intended to continue monitoring the trial to assess both short and long-term performance of this innovative product. Using waste plastic in asphalt is seen as a cost-effective and environmentally friendly way of reducing the quantity of waste plastic that would otherwise require disposal at landfill sites; the intention of this paper is to share the technology used to produce the waste plastic modified asphalt as well as to present the performance that can be expected from the product.

Simon Tetley, Tony Lewis, Waynand Nortje, Deane Koekemoer, Herman Visser

Climate Resilient Road Design – 1

GIS Aided Vulnerability Assessment for Roads

Road networks are vulnerable to natural disasters such as floods, earthquakes and forest fires which can adversely affect the travel on the network. However, not all road links equally affect the travel conditions in a given network; typically some links are more critical to the network functioning than the others.The first stage of study involves the investigation of geological conditions. Image classification used for extracting information classes from ‘Geological Map of Istanbul area’ image file. The resulting raster layer used to create thematic map. A reclassification was performed for lithologic types. The second stage involves analyzing topological situation. A slope map prepared and classified according to percentage of slope values. The third phase is the analysis and interpretation of the accumulated data to establish suitable and applicable road vulnerability scores. The information in the source data for each vulnerability factor are classified into three different vulnerability scores: +2 (considerably increases vulnerability), +1 (increases vulnerability) and 0 (does not increase vulnerability) by using a vulnerability score table. The study area was categorized into three different traffic analysis zones as: (1) least favorable area; (2) favorable area; (3) most favorable area. Vulnerability values obtained to measure serviceability of critical links in dense urban road networks and applies them to the case of ‘Beyoğlu’ region.Thematic layers were prepared using the Geographic Information System (GIS), and they were then combined to produce the serviceability of road links in the ‘Beyoğlu’ region. Consequently, A site specific vulnerability index is proposed, considering the serviceability of road links. A conceptual flowchart of the GIS processing steps taken to obtain the vulnerability index is illustrated.

Berna Çalışkan, Ali Osman Atahan, Ali Sercan Kesten
Investigation of Historical and Future Air Temperature Changes in the UAE

Climate change refers to significant and long-term changes in the global climate. This climate change could alter different climate factors in future that affect the resilience of transportation systems such as temperature, precipitation, wind speed, solar radiation, and humidity. For example, global warming is expected to affect the design of the asphalt pavements and asphalt binder selection for roads construction in the UAE. This study aims at investigating potential historical trends of different climate factors using historical climate data collected from different weather stations from 1990 to 2020 to identify the factors that has more potential to change greatly in the future. This study considers historical and future air temperature records from automatic weather stations and airport weather stations. Initial analysis indicated that the historical air temperature trend seems to increase remarkably compared to other climate factors. The second part of this study focuses at investigating the future air temperature changes in the UAE. The prediction of future air temperature depends on 3 climate models used from the CMIP5 platform which is the fifth phase of The Intergovernmental Panel on Climate Change (IPCC). For all models used, 2 greenhouse gas concentration scenarios have been considered (RCP 4.5 and RCP 8.5). This study proposes required mitigation policies to minimize the global worming impact on the resilience of asphalt pavements in the UAE. And provide a climate profile for the country, which will be used in further research to predict pavement temperature, performance grade and pavement design, based on the MEPDG.

Reem N. Hassan, Waleed A. Zeiada, Muamer Abuzwidah, Sham M. Mirou, Ayat G. Ashour
Climate Teleconnections Contribution to Seasonal Precipitation Forecasts Using Hybrid Intelligent Model

Long-term precipitation forecasts can provide valuable information to help mitigate some of the outcome of floods and enhance water manage. This study aims to extract significant information from oceanic-atmospheric oscillations that could enhance seasonal precipitation forecasting. A hybrid AI-type data-driven artificial neural network model called MWD-NARX based on a non-linear autoregressive network with exogenous inputs coupled to multiresolution wavelet decomposition (MWD) is then developed in this work. First, MWD is used to decompose climatic indices and precipitation data. Then the NARX ensemble model allowed to identify the statistical links between the decomposed indices and the decomposed precipitation according to temporal scales and to predict each precipitation decomposition. Ensemble precipitation forecasts are carried out over horizons ranging from 1 to 6 months. For operational forecasting, the forecasts obtained from the decompositions are summed to represent the true precipitation forecast value. The seasonal forecasts of average precipitation by sub-basins (SBV) of the Medjerda are carried out. Large scale teleconnections ENSO, PDO, NAO, AO and as well as Mediterranean Oscillation were used as inputs to the model. The forecasting model coupled to data pre-processing method made it possible to produce very satisfactory forecasts of non-stationary data by extracting modes of variability. The results indicate that exogenous inputs like climatic indices clearly improves the accuracy of forecasts on 82% of SBVs and increases the forecast lead-time up to 6 months. This research is the first of its kind using a hybrid prediction approach by means of indices related to ocean-atmospheric oscillations in North Africa.

Rim Ouachani, Zoubeida Bargaoui, Taha Ouarda
Development of Pavement Temperature Prediction Models for Tropical Regions Incorporation into Flexible Pavement Design Framework

Asphalt pavements are affected by several factors such as traffic loading, materials properties, and environmental conditions. Of these, the environmental conditions have significantly influenced the long-term pavement performance since the variability in climatic factors affects the choice of materials used in pavement construction and rehabilitation. Therefore, collecting and using climatic data of a location becomes critical in selecting the right type of construction materials and the rational design of the pavement layers. Currently, the flexible pavement design guidelines in India do not incorporate real-time climatic data extracted from weather stations; instead, a standard climatic condition is assumed across the country that has diverse climates. To address this, this study was formulated with an object to develop a set of prediction models for estimating pavement temperatures over the entire duration of one full day, representative of any seasonal variation occurring annually in the tropical climate. The scope of the work encompassed: (a) development of mean monthly maximum (Mmax) and minimum (Mmin) temperature models based on the historical weather parameters and geographical coordinates collected from eight designated weather stations by the India Meteorological Department for ten years across the State of Andhra Pradesh, India covering 620 data points, (b) formulation of two different pavement temperature models corresponding to the half-day seasonal variation, and (c) establishment of generalized annual pavement temperature models for tropical regions for the developed Mmax and Mmin models. All the predicted models had high accuracy characterized by excellent statistical goodness of fit measures (R2adj > 90%; Se/Sy < 0.350).

Chaitanya Gubbala, Krishna Prapoorna Biligiri, Amarendra Kumar Sandra

Impacts of Transport Investments

Experiences of High Capacity Transport in Finland

The competitiveness of Finland’s industry with respect to logistics has been improved by increasing the maximum dimensions and masses of heavy goods vehicles. The maximum height of vehicles was increased from 4.2 m to 4.4 m and the maximum mass from 60 to 76 tons in 2013. The maximum length of vehicle combinations was increased up to 34.5 m in 2019. These new dimensions can be utilized on all public and private roads unless separately signposted.In order to prepare for this change, Finnish Transport and Communications Agency approved about 100 permits for testing of heavier and longer vehicles in 2013–2019. Fuel savings were up to 30% and cost of personnel can be up to 10–15% lower. No negative issues in traffic safety has been detected and bigger vehicle combinations are operating smoothly among other traffic.The experiences show that 1.6–3.2 billion euros can be saved in logistics costs over the next twenty years. The reform will help to reduce the carbon dioxide emissions by two percent a year. However, there is a need to strengthen roads and bridges, especially when pavements are thin (less than 100 mm). Tight crossings and turning lanes need improvements to enable long vehicles to negotiate turnings safely. So far needs to improve the infrastructure have been modest.Possibilities to increase maximum weights of vehicle combinations are under consideration, but this will need more investigations to ensure preservation of road condition and to develop a reliable access control system of vehicles.

Vesa Männistö
Impacts of Transportation Infrastructure Investments and Options for Sustainable Funding

The long-term viability of the motor fuels tax as a primary funding mechanism for transportation has been questioned for its effectiveness into the future. Vehicle fuel economy improvements, coinciding with substantive real purchasing power losses of the federal motor fuels tax in the United States (the federal tax rate has not been adjusted for inflation since 1993), have created uncertainty about how the motor fuels tax could sustainably finance the transportation system needs. Transportation agencies face historical revenue shortfalls, and important parts of the infrastructure require maintenance to sustain or improve their conditions.The State of North Carolina currently invests approximately $5 billion annually in its transportation system. This investment enables the state to achieve an overall infrastructure rating of mediocre. In this condition, the state is facing serious challenges affecting driver safety and economic productivity. Our economic analysis demonstrated that highway construction projects lead to immediate positive economic impacts in as few as two years after project completion. One key finding illustrated that the number of businesses within one mile of NC highway projects increased by 73% a rate that is 48% higher than the growth of business establishments within one mile of unimproved NC highways. Other studies have shown that the time to make capital investments, such as infrastructure, often has the most value in times of recession with increased spending and job creation.

Daniel J. Findley, Steven A. Bert, Weston Head, Nicolas Norboge, Kelly Fuller

Climate Resilient Road Design – 2

Climate Resilient Urban Mobility by Non-motorized Transport

African cities have begun to suffer climate change effects. In most African cities, populations are increasing rapidly and the reliance on Non-Motorized transport (NMT) is high, but dedicated NMT infrastructure remains underdeveloped. In all cities and towns across Uganda, the use of private vehicles has risen steadily over the years and has congested these cities, poisoned the air and killed NMT users at exceptionally high rates. This paper seeks to answer the question whether NMT projects are economically viable and how cities can maximize benefits of NMT for Climate conscious economic growth. This paper presents an Economic analysis of the NMT pilot project in Kampala using the Non-Motorized Transport Project Assessment Tool (NMT-PAT) to quantitatively and qualitatively analyze the expected impacts (benefits and costs) with focus on Environmental and Health Benefits. The results of the analysis indicate that considering a design life of 15 years, Kampala city will experience reductions in emissions to the tune of 675,000 tons for Carbon dioxide, 13.81 tons of Particulate matter and 2536 tons of Nitrogen dioxide. The health benefits in terms of reduction in accidents valued at Uganda shillings 4,163,611,405,517.35 (USD 1,134,499,020) will also be realized. A general improvement in journey quality, security and livability will also be achieved as well as a reduction in the noise levels by about 3.75 dB. To encapsulate by implementing the proposed NMT infrastructure, a Net present Value of 14 trillion shillings (USD 3 Billion) shall be realized thus demonstrating that NMT investment is viable.

Kigozi Joseph
Advances in Road Infrastructure and Mobility
herausgegeben von
Dr. Amin Akhnoukh
Prof. Dr. Kamil Kaloush
Mag. Magid Elabyad
Brendan Halleman
Nihal Erian
Samuel Enmon II
Cherylyn Henry
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