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12-01-2021 | Mobility Concepts | OriginalPaper | Article

Future of Mobility: Sustainability Is a Given, Efficiency The Measure

Rittmar von Helmolt, Martin Rothbart, Uwe Dieter Grebe
17:30 min reading time

The future of mobility will be characterized by sustainability and efficiency. In this article from the German-language Springer journal "Nachhaltige Industrie", automotive supplier AVL ventures a look into the future.

1. Introduction

Mobility is expression of freedom, and at the same time a necessary prerequisite, for supply, access to goods, education, work and culture. Mobility is affecting central areas of life, and history is characterized by the quest for faster locomotion with less physical effort. The automobile has played a central role in this since its invention. People's access to individual motorized mobility has never been easier than today. In Europe, there is one car for every two inhabitants, and more than 72% of all transportation is done by cari1 2.These figures have continued to rise over the past decade.

At the same time, however, there have never been so many regulations and restrictions affecting the vehicle and its operation. This is the result of the endeavor for meanwhile more than 50 years, to address the negative effects of the automotive success story through technical and regulatory measures: Traffic casualties, pollution, and congestion.

Increasingly complex regulations for vehicle safety and environmental compatibility primarily affect the vehicle manufacturer. Vehicle users, in addition, have to deal with a variety of issues arising from the use of public space. This is especially true in urban environments, where, on the one hand, the higher population and vehicle density makes the issues more apparent than in rural areas, and, on the other hand, alternatives are available that put the advantage and convenience of the automobile into perspective.

Besides air pollution, it has mainly been the low efficiency of the car in terms of the resources used – energy, capital and, above all, traffic space – which has long led urban and mobility planners to push the private car out of the urban environment.

Derived from these trends, which have a global and long-term impact, the past decade in the automotive industry has been characterized by questioning the business model. Indeed, the focus of activity has been shifted, at least to some extent: From hardware to software, from product to service.3

However, the transformation of the vehicle manufacturer into a mobility service provider has not taken place to the extent that some had predicted. There has been no lack of serious attempts to open up new business areas, but on the user side, too, the transformation of the mobility system has not been accepted in the expected way. Today, it must be stated that the new car- and ridesharing offerings have no significant contribution to daily transportation. For the car manufacturers, the investment in the development of mobility services has therefore not paid off to the expected extent in many cases, so that they are now withdrawing from them again, at least in part4 5

In the scientific discourse, a decrease in motorized individual transport was postulated for the most part, and political course settings were mostly made to favor public mass transport. As a result, the transport performance of public transport has also increased. However, individual transport has grown even faster. For example, the number of passenger cars in Europe has grown almost five times faster than the number of buses (Fig. 2).

Most recently, the spread of COVID-19 and associated measures have led to another very significant shift in user preferences in favor of personal transportation (cars and bicycles), while public and private collective transportation have experienced significant declines.

There are various statements about how quickly a recovery will take place, and there are also major regional differences. In any case, the abrupt changes in mobility behavior during 2020 provide a valuable data source for mobility researchers.

2. Drivers of tomorrow's mobility

Changes in the mobility system will only be successful if they are an improvement of the already existing offering, and environmental and sustainability criteria are currently weighted highest in most urban regions. Driving forces arise from a clear vision of the actors and acceptance by the user. Technical feasibility is a necessary prerequisite, and technical innovation is often also the triggering moment.

a) Vision. While policy guidance should follow a vision for a future mobility concept, transportation planning is however regularly predetermined by a variety of constraints. In urban areas, it is characterized by the struggle for clean air, avoidance of congestion, and competition for space with other mobility carriers, as well as functions of existence such as living, working, meeting, and recreation.

b) Acceptance. The task of any new mobility system is to create an offer that meets the needs of the user in essential respects. Acceptance is determined by the accessibility of the offer, the associated costs for the user, as well as the advantageousness compared to other solutions. It is enormously important to put this at the center of efforts and to make a honest effort to improve the offer. In free and open societies, it is unlikely to succeed in forcing the politically desired mobility solution with bans and restrictions on all other solutions.

c) Technical feasibility. Technical developments have regularly played a significant role in the evolution of mobility; from the invention of the wheel, to the steam engine, the car, the airplane, and the smartphone with ridesharing app. Systems which can build on existing infrastructure have a significant advantage (the car could use the same road as the carriage). High density of development in cities is limiting the options for new infrastructures, and thus, concepts are being thought up to open up the third dimension, including underground tunnels and airborne drones and taxis.

Furthermore, the target vision of the future mobility system itself is subject to changes. Urban planning masterminds have long recognized that spatial structures are largely responsible for traffic habits, and are actively addressing the redistribution of public space in the city.6 7  Nevertheless, except in large cities, comparatively little active change has been made to the structures as a whole, and changes often come in the form of fairly small-scale piecemeal efforts.

In contrast, digitization has a more lasting and global effect here, in a sense that basic functions such as shopping, working and education often no longer require a change of location. However, the transport of goods is necessary. These developments have been particularly visible and accelerated in 2020, and as a result will permanently change the structure of city centers in particular.

3. Efficiency of the vehicle: focus on the drivetrain

For many years, the discussion about future mobility was very much about improving air quality. In the U.S., new passenger vehicles are over 98 % cleaner for most tailpipe pollutants compared to the 1960s8. Pollutant limits also in the EU have been steadily reduced since 1970, and vehicles are becoming ever cleaner. Technical development has reached the level of "zero impact emission,"9 i.e., such a low level of pollutant emissions that the vehicle no longer has any impact on the environment or health.

As a result of the Kyoto Protocol of 1997 and later the Paris Climate Protection Agreement of 2015, CO2 efficiency has been added as an additional target parameter for propulsion. Since 2009, limits have been set10 for the CO2 emissions of the new vehicle fleet in the EU, whereby only the emissions of the drive system are taken into account (tank-to-wheel), while the emissions of the upstream chain (well-to-tank) are not considered. While this approach makes sense for pollutant emissions, for improvement of local air quality, it does not make sense for non-toxic climate gases such as CO2, whose climate impact is not changed by shifting them elsewhere in the well-to-wheel chain. For electric as well as hydrogen vehicles, all CO2 emissions occur during fuel production. Nevertheless, the vehicles are counted as zero-emission vehicles because this system has been retained in legislation to date.

The quantity and mix of primary energy sources ultimately used is decisive for CO2 emissions. A shift in the energy demand of the transport sector away from oil and towards other energy sources could influence this mix in such a way that less CO2 is emitted overall, but this is not guaranteed. Renewable energy today accounts for only a small fraction of about 15% of Germany's energy turnover, wind power and photovoltaics together even less than 5%. This amount cannot be increased significantly in the short term either, so that an extensive use of renewable energy in the transport sector may lead to a shortage elsewhere, where they might have to be compensated by fossil fuels at least in part.

By regulating vehicle exhaust and CO2 emissions, i.e. without taking the upstream chain into account, however, a clear dominance of electric drives, predominantly battery-electric in passenger cars, is predetermined. On the other hand, there are very controversial discussions regarding the design of the transition scenario.

While the U.S., especially California, has been the undisputed leader in global pollutant legislation for decades, fuel consumption and thus CO2 emissions have been much less of a focus there. In addition, the political steps taken in 2020 in the U.S. scenario show a relaxation rather than a tightening of CO2 legislation11. However, in contrast to European legislation, CO2 emissions from electricity production are included in the U.S. assessment. This is politically far-sighted and represents a significant step towards a "CO2 life cycle" or "cradle-to-grave" (CtG) assessment, the only truly relevant assessment basis for measures to reduce global CO2 emissions.

The calculation for a "CO2 life cycle" analysis is very complex and an exact determination, which is already difficult for fuel generation, requires assumptions for the entire future life cycle. Depending on the vehicle type, these are periods of about 15 to over 30 years12, over which the future development of emissions in power generation must be estimated, as well as how vehicles are recycled at the end of their life. These inaccuracies, but also non existing monitoring systems, make it difficult to anchor life cycle analyses sensibly in legislation, so that life cycle assessment isn’t incorporated in any laws yet.

However, at least public perception is already further advanced, especially in Europe, and various aspects of the overall CO2 footprint of the vehicle are already being discussed. Recent publications13 14 and our own calculations come to a differentiated and detailed understanding as to which drivetrain currently represents the most efficient option w.r.t. lifecycle CO2. This is due to the aforementioned uncertainty about the development of the energy mix over the vehicle's lifetime and about possible future recycling processes. What is clear, however, is that all technologies are challenged to become more efficient in terms of CO2 emissions. For each of the technologies, there are different levers to improve emissions over the life cycle of the vehicle (Figure 7). Significant reduction of lifecycle CO2 is possible for each technology, and for all of them could end up in the same range.

For the hybridized vehicle, largest potential is related to further increasing the efficiency of the drivetrain and the use of CO2-neutral fuels. However, their large-scale industrial introduction is not expected before 2030 and widespread availability not before 2050. For the battery electric vehicle, main levers are associated with cleaner battery production and the use of renewable energy in the electricity mix. Here, too, it will realistically take many years to significantly reduce CO2 emissions from electricity production overall, but at least regionally and at certain times, this is possible already today. For the fuel cell electric vehicle, the manufacturing of the fuel cells themselves and hydrogen production and distribution are the biggest points of attack. Hydrogen is 95% produced from fossil sources today, worsening the CO2 efficiency in this technology pathway. For the future, however, hydrogen is considered a promising energy carrier to transport and store renewable energy.

In the future, the efficient use of technologies will also be linked to individual usage behavior. For example, a battery-electric vehicle with low usage or mileage will have less chance of working off the CO2 deficit from production, but on the other hand may have the opportunity to be connected to the grid for a long time and only charge the battery when a surplus of electricity is available (Smart-charging). This logic can also be applied to larger vehicles such as buses. The design of the drivetrain can be optimized for the intended use; for a given usage profile, the battery should be no larger than necessary. The dependence on the usage profile is particularly clear for plug-in hybrid vehicles, which can be operated either on electric power or on gasoline or diesel. 15

4. Efficiency of land use: Driver for "Shared Mobility”

The design of a new mobility concept is also about the distribution of public space, and this poses a particular challenge for densely populated regions and cities. In the scarce urban space, the land-use competition for basic functions of living / doing business and mobility is particularly high.

The top priority is therefore efficient mobility solutions that make the best possible use of the space available for mobility. The figure compares the transport performance for the same path width for different modes of transport. As expected, collective transport is very capable, but also pedestrian and bicycle transport is comparatively efficient. Passenger cars perform poorly; and in addition to the simplified diagram, the required parking space would also have to be taken into account.

For large agglomerations with a corresponding population density, collective transport is an alternative to the private car that is well accepted. Smartphone apps for route planning and ticket purchasing have made mass transit use more attractive in recent years, even for people not familiar with the area.

As soon as you get to the outskirts, however, the quality of service regularly decreases even in urban regions. Furthermore, even in large cities, the car is advantageous in many specific cases, when e.g. heavy goods need to be transported, or a group or family is traveling, or sick or impaired people need to be driven.

For occasional trips or to save parking space, car sharing appears to be a good alternative to owning a car in some cases. Mobile Internet and "connected car" functions allow for flexible booking, pickup and return. However, professional operation of the vehicle by the carsharing company makes it somewhat more expensive than the private car. In addition, a driver's license and driving ability are still prerequisites. Despite considerable advertising and support from politicians, carsharing therefore still ekes out a niche existence. Even in Germany, where the largest carsharing fleet is deployed, only one in about 2,000 passenger cars is a carsharing vehicle (Fig. 9).

Ride-hailing or cabs, on the other hand, appear to be a more attractive option, as evidenced by the enormous success of the relevant platforms. In North American cities, ridesharing services have replaced cabs within a few years; cab and ridesharing trips combined have doubled in New York in just five years.

The reasons may be that users do not have to worry about the vehicle at all, and there is also no need to search for a parking space. The app enables a low-threshold offer, the fare and the route are transparently displayed in advance, and it is also cheaper than a conventional cab in many cases. As a result, many trips have also been won by ridesharing companies for which private cars were previously used.

Even with cab and ride-hailing, however, sustainable business models are hardly possible for the operator, since in addition to operating the car, considerable costs are incurred by paying a driver. The hope for a profitable business with these services is fueled by the fact that at some point a driver will no longer be necessary and the vehicle will be able to travel autonomously.

Technically, this will be feasible in the next few years; as of today (fall 2020), five companies have approval to begin16 operating driverless vehicles in San Francisco .

How great the effort will ultimately be can only be roughly estimated at present. In addition to the need to keep the complex technology in a safe condition, there are questions on licensing and the mode of operation. Today's ridesharing and cab services have a share of empty runs of up to 50%17 18, which is quite critical for the cost side of the business.

In addition to the economics, these empty trips are also ecologically problematic. The studies mentioned above have shown that the increase in ride-sharing services can increase pollutant emissions and traffic congestion. Autonomous vehicles will not change this situation19 20. As a matter of fact, by eliminating driver costs, this effect could even be intensified.

5. Key to acceptance: user orientation and optimization for operation

User acceptance is a mandatory requirement for implementing a successful mobility solution. The necessary prerequisites can be described with the following "A's":

Ability or accessibility - many people must be able to use the offer, and it has to be simple

Availability - the offer must meet the needs halfway (at the right time on the right route for as many as possible)

Affordability - the offer must be affordable for a large part of the population.

But this is not yet sufficient. For the mobility offer to actually be accepted, it must be competitive:

Advantageous - meaning to provide an advantage, more convenient, associated with time savings or a positive experience.

Apart from providing the vehicles themselves, technical innovations from the automotive industry have so far only been used to a limited extent. However, the tools and methods from technical development could make a good contribution if they are further developed to optimize the use of vehicles, and this optimization takes place in cooperation between vehicle developers, mobility service providers and fleet operators. The interface between technical development and fleet operator procurement can help to improve specifications for future vehicles and infrastructure for passenger transport and logistics.

This certainly applies to the future of driverless "people movers" and delivery vehicles, which will have to fit into urban traffic just as safely, quickly and energy-efficiently as today's vehicles. But even today's transportation vehicles have potential for improvement in order to be adapted to current requirements.

Two examples:

a) Flow simulation of air conditioning.

Mass transportation may be unattractive to users for the foreseeable future due to the increased risk of infection. If aerosols are causative for the transmission of diseases such as COVID-19, intelligent ventilation could already make a significant contribution to safety. Ideally, the individual passenger would be protected by an "air curtain" that is impenetrable to pathogens (Fig. 11). For design and optimization, the same tools can be used as for the simulation of the interior air conditioning (here in the example a passenger cabin). Even without a virus, it is probably more pleasant for many people to travel by bus or train if fresh air is provided by well-designed ventilation.

b) Measurement from vehicle fleets and powertrain simulation.

The optimization of vehicles for their respective operations also affects the choice of powertrain, which often initially appears secondary when considering the "big picture". On closer inspection, however, it is an important parameter and an effective lever for efficiency improvements. For example, in the electrification strategy for a city bus fleet - in addition to the costs of vehicle procurement and infrastructure - the influences of charging time and battery weight on the performance of the transport system must also be taken into account. Modern vehicle and fleet simulation methods help to reduce costs and optimize reliability and energy consumption based on data collection in the existing fleet. Figure 12 shows data from a project in which city buses were measured in real-world operation, and results were used to provide guidance for the future operation of electric buses. The measurement was carried out in real operation and over a longer period of time to record different weather and operating conditions. With the subsequent simulation with different bus types, predictions have been made for support the planning for fleet conversion, and to avoid surprises in real operation.

6. Conclusion and outlook

The shocks of 2020 have also had a significant impact on mobility systems. Some developments have accelerated considerably, while others may have been discarded or terminated too early.

"The auto industry will change more in the next five to ten years than it has in the past fifty"23. This sentence probably applies even more to the mobility system as a whole.

While the development will continue to be rather non-linear, and is thus not very predictable, the long-term trends will however endure:

Efficiency in terms of resources used, energy and space requirements, will remain a strong driver for change; Defossilization and the transition to a circular economy are important and long-term tasks that will probably still not be completed in 2050; Technical mobility innovations can also have a disruptive effect in the future

Digitization, the associated mobility services, and ultimately the introduction of autonomous vehicles have the potential to change transportation from the ground up. Decisive factor for widespread and sustainable implementation and adoption of any transportation innovation, however, will be whether the overall system is more efficient and convenient than it is today.

[1] EU Transport in figures, statistical pocket book 2019
[2] ACEA pocket book 2020/21 (272 million registered passenger cars out of a population of 513 million in 2018).
[3] "Shared Mobility - A Car OEM business? " R. von Helmolt, wocomoco Congress, Innsbruck 2015,
[4] „Kaufangebot für FreeNow” (durch Uber) und „Deutsche Bahn kauft Daimler und BMW Teil von YouNow ab“, in German, Manager Magazin, Oct. 21 and 22, 2020.
[5] „Teure Flotte: Der Carsharing-Flop von Daimler und BMW“, in German, Handelsblatt article, Dec. 19, 2019.
[6] Eurostat, Data from European Environmental Agency, 2019
[7] UK Department for Transport, data retrieved from, October 2020.
[8] Representative is Jan Gehl, one of the most influential urban planners of our time. E.g. "Cities for People", Island Press, 2010
[9] "Traffic Space Is Public Space: A Handbook for Transformation", A. Degros, S. Bendix, Park Books, 2020
[10] United States Environmental Protection Agency,
[11] C. Martin et. al., Zero Impact Emission vs. Affordability -The ICE as Part of the Solution, 2020
[12] EU Regulation (EC) No. 443/2009, most recently No. 2019/613.
[13] AG Energiebilanzen e.V.. (
[14] EPA, Regulations for Greenhouse Gas Emissions from Passenger Cars and Trucks,, letzter Aufruf: 10-2020
[15] Even for the actual useful life, there are only imprecise figures, e.g. from the disposal company. In Germany, more than 75% of vehicles are exported at the end of their useful life and continued to be operated or recycled elsewhere.;
[16] according to G.Fraidl, AVL , February 2020
[17] Auke Hoekstra et. al, TU Endhoven, Comparing the lifetime green house gas emissions of electric cars with the emissions of cars using gasoline or diesel, 09-2020
[18] FVV, Cradle-to-Grave Life Cycle Analysis in the Mobility Sector, , 06-2020
[19] "How sustainable is electric mobility? Cradle-to-cradle study of different drive systems", U. D. Grebe, Keynote auf ATZ live Tagung, Mannheim, November 2019
[20] "Schrödinger's Car," Emissions Analytics newsletter (, Oct. 22, 2020.
[21] Guideline values, depending on occupation density, speed profile and size of vehicles. Asian Development Bank. Deutsche Gesellschaft für internationale Zusammenarbeit (2011): "Changing Course in Urban Transport: An Illustrated Guide".
[22] Data from Bundesverband Carsharing, 2020 (
[23] TLC Trip Record Data on (
[24] California Department of Motor Vehicles,, (abgerufen am 22.10.2020)
[25] "Investigating the transportation efficiency of ride-hailing services by considering empty trips in the case of Austin, Texas", OĞUZ TENGILIMOĞLU, Dissertation, University of Leeds, 2019
[26] Union of Concerned Scientists, (abgerufen am 22.10.2020)
[27] "Induced traffic by autonomous vehicles: an assessment," S. Hörl et al, ETH Zurich, 2019.
[28] "Urban Mobility System Upgrade: How shared self-driving cars could change city traffic", International Transport Forum, OECD, 2015
[29] Vehicle design and thermal simulation: AVL
[30] Measurement on city buses: Graz Holding; AVL.
[31] Mary Barra, CEO of General Motors, at the World Economic Forum in Davos 2016.

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