A Pathway to Safe, Smart, and Resilient Road and Mobility Networks

Despite the availability of mobile applications designed for evaluating the superficial conditions of pavement structures based on the International Roughness Index (IRI), their effectiveness for urban pavement is not yet proven. The driving conditions and particular road characteristics influence the effect of the variables on the dynamic response captured by the mobile application to estimate the IRI. Additionally, the variability of the IRI is increased due to the complexity of controlling many variables involved. To estimate the IRI in urban roads using a mobile application (IRIm), these values need to be adjusted using mathematical models. Furthermore, some controlled variables must be fixed at specific values to reduce estimation errors. This study analyzes the influence and interaction of controllable variables on the IRIm to reduce their variability. The first stage of the methodology was exploratory, allowing us to select a subset of independent variables. In the second, an experimental design was applied to analyze the effect of the variables and their interactions on the IRIm. Findings suggest that IRIms are sensitive to specific variables. However, in this study, in a vehicle integrated with a low-performance suspension system, setting the tire pressure to three psi below the recommended manufacturer level and driving the vehicle close to 35 km/h, the IRIms were slightly affected by small changes in these factors. These results show that mobile applications can provide consistent and reliable measurements to estimate the roughness of roads under certain conditions. This investigation is a starting point for future research focused to propose a protocol for estimating the IRI using mobile applications.

Climate condition in Mongolia is severe, and air temperature in winter reaches −40 °C. Low temperature cracks (LTC) are found at asphalt pavement widely in Mongolia. Saw-cut joints with every 10, 30 and 50 m are introduced at new asphalt pavement as a countermeasure for LTC based on past research at Canada, Alaska and so on, because materials including bitumen are limited and it seems that controlling LTC in advance is cost-effective. From above test pavement results, it seems that 10 m-separation section has fewer LTC after 2021–2022 winter season. And similar cracks are found at shoulder with unbound materials. In general, frost heave occurs in severe winter and unbound materials move upward. But there is no upward movement at shoulder nor asphalt pavement. A technical paper in Japan said that the development of ice crystals due to the movement of pore water is small and shrinkage due to changes in soil structure is greater in low-saturation soil. Moisture contents of the unbound materials are low, and winter in Mongolia is dry in practice. The authors think that similar phenomena have been occurred there and they are LTC of unbound materials. Most LTC at asphalt pavement and LTC at unbound materials are connected each other. And some are at asphalt pavement only or at unbound materials only. Follow-up survey is required to know this cracking and that saw-cut joints are effective or not.

Hot Mix Asphalt (HMA) pavements are the backbone of the transportation economy in terms of roads and airports for the Southeast Asia (SEA) region. There is a plethora of approaches in terms of materials, design techniques and construction strategies that can render a pavement long lasting. While there are several techniques that can be adopted by the SEA infrastructure agencies, the determination of the usefulness of each approach requires very large investments in time and resources. Identifying this gap, in this paper we examine two approaches of sustainable HMA pavement development for the SEA (a) modifying existing conventional materials and techniques and (b) examining next generation materials and techniques. The authors have taken the example of Southeast Asia Country to be used as the case analysis where we have developed reference material and design specifications in addition to examining the development of both physical and human resources and the estimated costs therein. Special focus is paid to the integration of locally available materials and the local environment/sustainability targets into this case analysis. Lastly, the authors propose a phased year wise transition plan for moving from the current level of HMA pavement construction to an integrated sustainable pavement construction toward creation of long-lasting HMA assets. The authors have endeavoured to ensure that approach followed can be replicated for any SEA countries by replacement of country-level policies and specifications.

The length of Japanese expressway operated by NEXCO-West has reached about 3500 km, and half of them have been in service for more than 30 years. In order to provide safe, secure, and comfortable pavement condition, a pavement management cycle, which focuses on extending the service life of pavements, must be implemented. Pavement monitoring is classified as routine inspections by daily patrol and road surface condition surveys every 1–3 years. Maintenance including crack sealing and patching is planed based on the results of daily inspections, and rehabilitation, as cutting overlays, is planned based on the results of road surface condition surveys, each of which is managed independently. Therefore, the information from daily inspections may not be fully utilized in the rehabilitation planning. In this study, we analyzed the deterioration trend of expressway pavements by linking daily inspection data, road surface condition survey data, and as-built pavement information based on location information such as routes, lanes, and kilo-posts. As a result, a concept for repair design that contributes to service life extension was derived from the relationship between IRI value and asphalt pavement thickness. In addition, the relationship between the frequency of defects reported in daily inspections and the progression of IRI value led to the concept of prioritizing repair locations. Based on these concepts, we propose an efficient and effective expressway pavement management.

The increase in disasters occurring in recent years suggests the urgency for thorough emergency response systems, particularly in the Caribbean. These countries are quite vulnerable to disasters such as hurricanes, and recovery from such events can be timely and devastating. The transportation system can be severely damaged during these disasters, in particular the infrastructures such as roads, ports and airports can suffer considerable damage impacting the economy and living conditions in these countries. Thus, there is a need for incorporating transportation planning into emergency planning. Safe evacuation and movement during disasters require collaboration of transportation experts, emergency managers and other stakeholders. This becomes more difficult as the population and vehicle ownership of the Caribbean region grows. This study analyses existing disaster management plans from different Caribbean countries. It highlights the lack of a comprehensive transportation components in these disaster management plan. Furthermore, the paper features key elements that are needed for the future design of a transportation disaster management plan within the Caribbean.

In Japanese expressway pavements, deeper layers are damaged due to the change of surface layer material from dense-graded pavements to high-performance pavements and the decline of structural load-bearing capacity caused by deterioration. In practice, stratified repair is conducted depending on the state of damage, and therefore, road managers need to determine the most suitable repair layer while simultaneously considering repairing damage and reducing construction costs and economic loss due to traffic restrictions. For that purpose, it is necessary to quantitatively evaluate how much the structural load-bearing capacity has been restored by the stratified repair and clarify the relationship between the effect of the stratified repair and the structural load-bearing capacity. In this study, the authors attempt statistical modeling of the state of structural road-bearing capacity. Specifically, the authors propose a hidden Markov deterioration model for expressway pavements that describes the transition of the load-bearing capacity of the pavement structure with a combined process, which consists of (1) a process of deterioration with age and (2) a process of recovery through repair. With this, it is possible to not only predict the decline in structural load-bearing capacity, but also quantitatively evaluate the degree of recovery at the time of repair as a transition probability. Furthermore, the authors conduct an empirical analysis of the proposed model based on the load-bearing capacity evaluation by FWD (Falling Weight Deflectometer) data conducted on the expressway and discuss the usefulness of the model.

The construction industry represents approximately 10% of the United States gross domestic product with a total of $2.0 T expenditure. As a result, cement production and consumption has been exponentially increasing over the past few decades. The increase in cement manufacturing is responsible for the environmental degradation across the United States and on a global scale. This research paper presents the GPC mix design, production, and advantages. In addition, it highlights the possible use of geopolymer concrete (GPC) in lieu of ordinary portland cement concrete (OPC) and lists the major impediments to the widespread of GPC in construction industry. GPC depends on the activation of high silica content in natural or industrial byproduct materials, as fly ash using alkaline solution to produce three-dimensional polymers that bind the aggregate instead of hydrated portland cement. Thus, cement consumption could be reduced or possibly eliminated. In addition to its environmental advantages, geopolymer water-free activation results in concrete mixes that is more resistant to alkali-aggregate reactivity, more resistant to chloride attacks, and less susceptible to shrinkage and early age cracking. The widespread of GPC in construction industry, especially in infrastructure projects, with massive exposure to chloride attacks, will result in a reduced need to project maintenance and repairs, and improve the overall condition of infrastructure projects.

The ultra-high-performance concrete (UHPC), developed in France in late 1990s under the name reactive powder concrete (RPC), is currently used by the Federal Highway Administration (FHWA) and State Departments of Transportation (DOTs) in different infrastructure applications. Major emphasis is given to precast/prestressed girder bridge construction, with an eye on increasing bridge spans, reducing the number of girders, and decreasing the girders depth. The aforementioned advantages are attained due to the superior characteristics and enhanced mechanical properties of the UHPC mixes, mainly increased compressive strength and modulus of elasticity. Despite the mechanical advantages and superior long-term performance, the UHPC market share is considerably small, and the number of UHPC bridges is limited. However, UHPC is being used in small-size repairs, casting connections, and joints. The main impediments to the widespread of UHPC in bridge construction is attributed to the high material cost of proprietary mixes ($2000 per cubic yard), lack of design specifications and construction expertise in handling UHPC construction projects. This paper presents current and possible future applications of UHPC. In addition, it presents a detailed study on current UHPC practices, advantages, disadvantages, and main impediments to the widespread of UHPC in bridge construction industry.

In this study, we tried to verify the performance of the BH girder, a new type of prestressed concrete (PSC) bulb-T shape with half-slab girder, as a part of the beneficial solution of long span highway and railway bridges. A 60-m-span BH girder was designed under the BS code. Finally, a 60-m-span specimen was manufactured and tested in Malaysia for static performance analysis. In addition, this paper also introduces the dynamic responses of the BH girder for railway bridges under Korean Railway Design Code. Railway bridge can cause dynamic problems because they suffer repetitive load due to the running train. In order to ensure the dynamic stability, railway bridges must thus satisfy thorough vibration limits as well as vertical deflection limits. In view of tendency to increase span, 45 m span of BH girder were adopted for double track and single track. All sections were designed under the Korean Railway Design Code, and three-dimensional modeling was built to be suitable for carrying out moving load analysis. Finally dynamic performance was analyzed compared to the limitations of the design criteria.

The wet method technology of using crumb rubber from recycled tires as a modifier of asphalt (bitumen) binder started to be used in Arizona and California in the 1970s. The crumb rubber wet process is a practical means of providing environmental, economic, sustainable, and safety benefits from using crumb rubber from recycled tires using the wet method technology widely used for societal benefits. New imaginative and innovative engineering technology concepts have led to the development of a new crumb rubber semi-wet method material. The new semi-wet method employs reacted and activated rubber (RAR). The RAR semi-wet method has demonstrated a product capable of matching and surpassing the performance of traditional hot mix asphalt and the traditional crumb rubber wet method asphalt. Basically, RAR consists of pre-treated and pre-reacted rubber that can be used directly in a mix plant just like a “filler”, thus it is easy to handle and requires no special equipment for blending crumb rubber and asphalt and no additional heat source. The RAR dry filler when it meets hot asphalt amalgamates in such a way as to become like the traditional crumb rubber method asphalt rubber. This paper provides the concepts and some experiences of mixes with RAR and presents how the added flexible fatigue cracking resistance of these mixes leads to great environmental and sustainability benefits.

Portland cement concrete with compressive strength ranging from 28 to 56 MPa are widely used in today’s construction market. Recently, the need for smaller structural sections necessitated the development of concrete mixes with higher strength and superior mechanical properties to satisfy the construction market needs. This paper presents the impact of using micro-sized supplementary cementitious materials (SCMs) as silica fume, quartz flour, and fly ash on the final compressive strength of concrete. SCMs are used to replace up to 30% of cement (by weight), which improves the sustainability and environmental compliance of construction projects as it lowers the carbon footprint developed due to cement manufacturing. In this research project, high-energy mixers were used in mix development, and high-range water reducers were incorporated to attain sufficient workability while maintaining the mix’s high strength. Concrete mixes with 28-day compressive strength of 100 MPa were achieved. The main advantages of high-strength SCM-incorporated mixes include the development of smaller structural sections, reducing material consumption, and reducing the need for frequent future maintenance. The inclusion of SCMs in concrete mix development significantly increases the project sustainability. SCMs incorporation in the construction industry will positively impact the infrastructure conditions within the United States.

In the research project presented here, the focus was on the design, manufacture, and incorporation of a hybrid fabric made of natural fibers, which can detect changes in the condition of the surrounding components by means of integrated sensor technology. The aim was to incorporate the functionalized fabric into the asphalt base layer of road pavements in order to detect structural damage to the layer. At the core of the fabric is a sensor material that is stretched by stresses and the electrical resistance is changed. The data obtained from the road is interpreted with the help of sensored test specimens loaded under laboratory conditions. In this way, signals and patterns can be assigned to the respective type of damage and its severity. This enables a statement to be made about the fatigue condition of the asphalt base layer without having to take samples on site. Furthermore, the condition can now be monitored continuously and over a large area. To this end, a software solution was developed that uses adapted machine learning methods to learn the relationship between an electrical voltage measured in the fabric and the condition of the asphalt base layer determined by load tests. With the aid of this software, the degradation state can then be interpreted exclusively from the data measured in the fabric and presented in the form of a few key figures. From this, appropriate recommendations for rehabilitation work can be derived directly in practical use.

The aim of the investigations is to establish a non-destructive testing method for the condition of asphalt roads. For this purpose, a sensor system is inserted into the asphalt layers during construction. In the recent developments, Rayleigh scattering-based distributed optical-fiber sensors (DOFS) have been used increasingly for measurements at barely accessible locations, for which the base layer of a road is an example. This paper explores the feasibility of embedded distributed optical-fiber sensors in asphalt roads to record the fatigue behavior. To confirm the validity of the measurement results, extensive preliminary tests and comparative measurements are carried out. The cyclic indirect tensile test [CITT, in accordance with (FGSV, 2018)] has been used to determine the fatigue behavior of asphalt, where modified Marshall Specimen (MS) with integrated DOFS has been used. It is shown that the modifications have no influence on the fatigue behavior. The DOFS allows to measure with a high spatial resolution, where the conventional method only acquires one value per time step. The horizontal strain function of an undamaged MS in dependence of time and space in the CITT can be perfectly matched to a Gausian-sinusoidal-3D-fit, which subsequently can be applied to Young-modulus calculations. Obvious deviations from the fit could be used for crack detection in asphalt structures. Furthermore, it is discussed how the lab-scale results can be used for the implementation of DOFS in asphalt roads.

The biggest problems of today are the carbon emissions caused by the vehicles together with the time spent in traffic. This problem has come to the forefront in the last 10 years, especially in cities with high population density and high immigration rates due to industrial zones and high job opportunities. Istanbul is a metropolis with a registered population of 16 million and home to approximately 20% of Turkey’s total population. According to the March 2022 data of the Turkish Statistical Institute, the number of registered vehicles in Istanbul is 4,714,138. The increase in the number of vehicles in proportion to the high population caused an increase in the time spent in traffic and an increase for carbon emitted from the vehicles. In the report “Black Report 2021: Air Pollution and Health Effects” published by the Right to Clean Air Platform, it is stated that air pollution in Istanbul is at a sensitive level. The intersection of carbon emissions and traffic congestion is traffic signalization. The Adaptive Traffic Management System, which is the most advanced of the signalized intersection management systems, was developed by the engineers within the R&D Center of Istanbul IT and Smart City Technologies INC (ISBAK INC), an affiliated company of Istanbul Metropolitan Municipality, and started to be implemented in the field in 2012 under the brand name ATAK. By using the Genetic Algorithm and Fuzzy Logic methods, the system that automatically determines the signal times at the intersections ensures that the waiting times are minimized and the congestion occurring in the intersection area is prevented.

In Japan, Green Slow Mobility (GSM) is promoted now. The GSM services have been introduced as a solution for first/last mile mobility issue. The word “Green” means that vehicles are normally using EVs. The word “Slow” rules the speeds of vehicles being slower than 20 km/h in operation. Japan is number one super-aged country in the World. The mobility issue for the elderly is a very serious social issue. In many areas, the GSM services have or will have contributed to give the first/last mile mobility solutions for all people, which are especially welcomed by the elderly. Another important purpose is to provide a sustainable service in the areas where the population decreased and aged rapidly. As for this point, a self-driving car/autonomous car/driverless car is mostly expected. At present, most in-operation services or experiments are not using driverless vehicles in Japan. However, several challenges have been in operation already. Although there are not enough examples/cases to draw a conclusion, a review of the experiences in Japan may encourage us to think about how the roads will change in the coming years. In this paper, the author is to describe the present experiences of the GSM services in Japan. Then the plans to promote the driverless vehicles are introduced. Consequently, how the roads may change is discussed.

The increasing urbanization, which leads to an increase in traffic density, the new road user groups, such as e-scooter riders, the increasing number of accidents among the vulnerable road users, and the demands for environmentally friendly mobility point out the need to rethink the current transport infrastructure and the associated road safety concepts. This study is the result of a joint research project conducted by the University of Applied Sciences Berlin and the Inspectio Research Institute in Munich. The aim of this work has been to survey the gaze behavior of e-scooter riders and to generate initial insights into their perception. An analysis of the gaze behavior has been carried out for road sections and for junctions. The gaze behavior on protected bike lanes differs significantly from the one on bike lanes on the roadway, where e-scooter riders focused on areas to the right and left, so that they lose visual and concentration capacities. The analysis of the gaze behavior on junctions shows that the eyes are directed more toward the road and the area directly in front of the e-scooter (nearfield), which results in reduced attention to the actual traffic situation. Based on the results, recommendations have been derived for the planning of new construction or conversion of cycling facilities. From the perspective of road safety, protected cycle lanes are the optimal solution compared to other infrastructure solutions, as they require less widespread gaze behavior and e-scooter riders can concentrate on the actual traffic situation.

Traffic-related fatalities account for 13% of death toll in Dubai alone. This issue is so prevalent that it spurred a bold global initiative to aggressively reduce traffic-related fatalities and/or injuries, which have formally become known as Vision Zero. One approach toward “Vision Zero” is to employ systematic and tailored technology solutions that improve driver’s competence level. Among those solutions are the driving simulators and the smart behavior evaluation systems that are realized to improve driver’s impression of road safety and potentially heighten their awareness of speed on attention, response time, and behavior. In this work, we will utilize the abundance of such data sets to systematically infer trends and relationship between the simulator/smart systems parameters and end target objective, namely the traffic-related fatalities/injuries. First, we present a demographic overview of the batch on which we will carry the statistical analysis. Each individual in the batch undertook both simulator test and practical test (i.e. practical test). We have studied the correlation between both test scores in light of the passing grade of the practical test. The categorical forms of the scores were considered to infer possible correlation. Results showed that the passing grade can influence the degree of effect the simulator score on the actual student’s performance during practical examination.

The Philippines has been leading an internal transformation toward improving road safety which has been accompanied and supported by the World Bank and its Global Road Safety Facility (GRSF). This paper gives an overview of the World Bank’s activities with the Government of the Philippines (GOP) through lending operations and technical assistance projects while highlighting the importance of a strong commitment from national and local authorities, stakeholders, and Non-Government Organizations (NGOs). This overview illustrates the experiences from these interventions and how working with local stakeholders ensures the sustainability of systems and projects. The support given by the World Bank from 2019 to 2022 included: lending operations such as the Cebu and the Manila Bus Rapid Transit Project, which have been accompanied by road safety audits, and the Mindanao Transport Connectivity Improvement Project, which consists of a systematic road safety program. Technical assistances were also carried out, including the implementation of Data for Road Incident Visualization Evaluation and Reporting (DRIVER); Road Safety Reimbursable Advisory Service (RAS), the Mindanao Transport Connectivity Technical Assistance (TA); Active Transport Development in the Philippines; and the Assessment of Vehicle Inspection Systems AVIS for the Philippines. Part of the success of the Philippines in improving road safety during these engagements includes a systematic approach through various tools involving multiple stakeholders. These stated elements have been conveyed by a strong ownership and leadership by country counterparts and different government departments’ senior management, who have been leading by example as active participants from the activities and capacity building. The other key features from this collaboration have been the evidence-based and institutional sustainability approach, in terms of carrying out an assessment of the institutional capacity and working on measures to strengthen it. This collaboration also focuses on data-driven interventions and best international practices within local context and needs through tailored capacity building and hands-on training, while mainstreaming road safety practice through the reviewed and improved national guidelines.