The trend towards increasing digitalization is also apparent in the transport system: Following driverless systems in industry and on rails, recently, trends towards automation and connection in road transport are also on the rise. These trends are often associated with the idea that many of today’s transport system’s problems can be solved by the complete automation of transport: cheaper, faster and more flexible traffic without congestion, with one hundred percent accessibility, no accidents and much lower emissions. However, there is no agreement among the experts whether or not these ideals can actually be achieved and when. With regard to the climate targets of the German government for the transport sector, it is important to be able to estimate the direct impacts that automation and connection can have on greenhouse gas emissions (GHG). There is the need to determine in good time whether the advantages of automation could lead to increased traffic on the roads – which might reduce any efficiency gains (rebound effect).

Together with its project partners, the Fraunhofer Institute for Systems and Innovation Research ISI has published the study “The effects of automated and connected vehicles in road transport on energy and greenhouse gases”. This potential analysis explores the possible technology developments in road transport up to 2050 in Germany. It shows the process of the transition to automated and connected driving, including the impacts on the transport system and GHG emissions.

The researchers quantified the GHG reduction potentials for eight types of vehicle (compact, medium and luxury passenger cars, heavy and light-duty commercial vehicles, city buses, long-distance coaches and minibuses) by estimating the market rollout for five stages of automation – from assisted driving to driverless vehicles. They used literature analyses and stakeholder dialogs to examine the technical feasibility of automation, the development of the production costs and user prices of the technology as well as buyers’ acceptance and willingness to pay more.

High market penetration for trucks and buses  

The calculations show rapid market penetration, especially for heavy-duty trucks and coaches: up to 90 percent of heavy-duty trucks and up to 75 percent of coaches are expected to be automated by 2050. One important reason for this: although there are initially higher investment costs due to installing the technology for automation and connection (about 24,000 euros when first introduced to the market), the costs for drivers, insurance and fuel drop significantly – possibly by up to 33 percent per kilometer travelled.

The researchers were surprised by the results of the market rollout for passenger vehicles: Up to 2050, the market share of driverless passenger cars is limited to 7 percent of the total stock of cars. For the luxury car segment, the driverless share amounts to 21 percent and to 57 percent for fully automated cars. Dr. Michael Krail, who coordinates the project at Fraunhofer ISI, explains the reasons for this: “The additional cost of equipping passenger cars with level 5 automation functions starts at around 11,000 euros when first introduced to the market and then decreases minimally to about 5,000 euros due to economies of scale effects. This means that the prices for buyers of small and compact cars are still in a range that few are prepared to invest in”.

The research team estimated the reduction potentials for GHG emissions based on a detailed literature analysis and stakeholder dialogs. Driverless systems make more efficient driving possible by reducing braking and accelerating, optimizing route choice and improving traffic flow. Dr. Michael Krail classifies the potentials: “Field tests conducted across Europe with partially and highly automated vehicles have demonstrated the efficiency potentials of the technology in real-life operation. Therefore, fuel savings of up to 17 percent seem possible for heavy trucks compared to non-automated vehicles and not only in theory“.

Possible savings of 7.8 megatonnes of CO₂ equivalent

Using the transport model ASTRA developed at Fraunhofer ISI, the team estimated how the market rollout of automation technologies will affect the distribution of all trips across the different modes of transport (modal split). If the rising share of electrified vehicles is taken into account, the GHG emissions from transport in Germany will decrease by 7.6 percent due to automated and connected vehicles up to 2050 compared to the reference case without such vehicles. This corresponds to 7.8 megatonnes of CO₂ equivalent. There is already a reduction potential of 5.2 megatonnes of CO₂ equivalent in 2030, even before the introduction of completely driverless vehicles.

According to the authors, the introduction of automation to road transport will lead to increased mileages on the roads, but these are more than offset by the high efficiency potentials. However, greater savings can only be achieved if there is a corresponding parallel increase in shared mobility services. If, for example, there is an increase in the demand for and supply of shared mobility services like ridesharing due to door-to-door solutions with driverless vehicles, then automation can contribute to an additional improvement in the efficiency of the entire transport system. However, care must be taken that the advantages of automation do not lead to a shift away from public towards private transport – because the additional trips could then outweigh the positive saving effects. This rebound effect must be avoided.

The study “The effects of automated and connected vehicles in road transport on energy and greenhouse gases” was conducted as part of the Mobility and Fuels Strategy of the Federal Ministry of Transport. It was produced by the Fraunhofer Institute for Systems and Innovation Research ISI in cooperation with the Fraunhofer Institute for Material Flow and Logistics IML, the PTV Group, the Hamburg University of Technology TUHH and M-Five.

The Fraunhofer Institute for Systems and Innovation Research ISI analyzes the origins and impacts of innovations. We research the short- and long-term developments of innovation processes and the impacts of new technologies and services on society. On this basis, we are able to provide our clients from industry, politics and science with recommendations for action and perspectives for key decisions. Our expertise is founded on our scientific competence as well as an interdisciplinary and systemic research approach.