Limited climate protection

Limited climate protection potential through automated driving

What is the potential of self-driving cars to reduce CO2 emissions? If one believes Fraunhofer researchers, then it is rather small. Above all, they warn of the rebound effect. Current analyzes of Tsinghua and Princeton University confirm the German scientists.

Autonomous cars still exist only in test mode, but already today there is great interest in such vehicles. Every third car buyer (33 percent) can imagine buying an autonomous vehicle. Among the young people between the ages of 16 and 29, the proportion is even significantly higher at 41 percent, as the digital association Bitkom found out in a survey among 1,003 Germans.

The interest of people in self-driving cars is often based on the fact that the automation of traffic promises to be able to solve many problems of our current transport system, as well as Springer-author Jochen Wittmann in chapter Acceptance of disruptive technologies - exemplified in automated driving using Youtube- Analyzes from the book Logistics in the Change of Time - From Production Control to Networked Supply Chains describes. Automated and connected driving should transform mobility to a cost-effective, flexible and climate-friendly transport system. However, the experts disagree as to whether this ideal will actually materialize.

Blessing for the environment or a disaster?
Basically, autonomous vehicles could influence greenhouse gas (GHG) emissions in a variety of ways. For this purpose, the vehicles would have to be used efficiently and shared in almost all journeys, the individual ownership of cars would have to be reduced. A programmed, energy-saving driving style could also reduce the energy consumption of the vehicles. A bad scenario for the environment would be: Self-driving cars continue to be operated privately and run on internal combustion engines. Because autonomous cars are so comfortable, there is also a risk that the number of kilometers driven will even increase and that public water traffic will be dug up.

The latest findings tend to make restrained concerns about climate protection. Research by Chinese Tsinghua University, which relates to the Chinese passenger car fleet, suggests that autonomous vehicles will not significantly affect greenhouse gases in the medium term. Although autonomous vehicles are comfortable, it will take a long time in China before the private car disappears. According to the scientists, it would only be possible to reduce GHG emissions by using autonomous vehicles between 2045 and 2050. Whether or not GHG emissions can be reduced will also depend heavily on the political framework conditions, as investigations by Princeton University suggest. In order to achieve the best possible environmental impact, autonomous vehicles should be used in managed fleets rather than private vehicles and should be subject to strict fuel efficiency requirements.

Impact on the transport system and GHG emissions
The Fraunhofer Institute for Systems and Innovation Research (ISI), which has studied in detail how autonomous driving in particular affects GHG emissions in Germany, also achieves comparable results. The study "Energy and Greenhouse Gas Effects of Automated and Connected Driving in Road Traffic" analyzes, together with project partners, possible developments in road transport technology up to the year 2050. It shows the process of transition to automated and networked driving including effects on the traffic system and on the GHG emissions.

The scientists quantified the potential for reducing GHG emissions for eight types of vehicles (compact, mid-size and luxury-class passenger cars, heavy and light commercial vehicles as well as urban, travel and minibuses) by monitoring the market ramp-up for five automation levels - from assisted to full-scale driverless driving - appraised. Using literature analyzes and stakeholder dialogues, they examined the technical feasibility of automation, the development of production costs and user prices of the technology as well as the acceptance and willingness to buy at buyers.

High market penetration of trucks and buses
The calculations show a fast market penetration especially for heavy trucks and coaches: By 2050, up to 90 percent of driverless heavy trucks and up to 75 percent of driverless coaches are expected. One important reason: Although there are higher investment costs due to the integration of the technology for automation and networking (around € 24,000 at market launch), the costs for drivers, insurance companies and fuels are falling significantly. Possible are up to 33 percent cost savings per kilometer driven.

In contrast, the results of the market ramp-up in the car sector are surprising: by 2050, the market share of driverless cars is limited to seven percent of the stock. For the segment of the upper class then results after all a share of 21 per cent driverless and 57 per cent fully automated car in the inventory. Reason are too high costs, the buyers of mid-size or small cars are not willing to pay.

Savings of 7.8 million tonnes of CO2 equivalents
Autonomous driving is interesting for climate protection because it enables smoother traffic with less braking and acceleration, as well as optimized route selection. The Fraunhofer ISI estimates based on tests with heavy trucks, that it is about a fuel saving of 17 percent compared to non-automated vehicles possible. Taking into account the increasing share of electrified vehicles, GHG emissions in the entire transport system in Germany should decrease by 7.6 percent by 2050 compared to the reference case without automation and networking. That corresponds to 7.8 million tonnes of CO2 equivalents. As early as 2030, and thus before the introduction of completely driverless driving, there would be a reduction potential of 5.2 million tonnes of CO2 equivalents. Considering that the federal government wants to reduce greenhouse gas emissions in traffic from the current 170 million tons of CO2 to less than 100 million tons by 2030, automated driving can only make a small contribution to reducing emissions.

According to the authors of the study, the introduction of automation in road traffic generally leads to increased road performance, which should, however, be overcompensated by the high efficiency potential. However, greater potential savings could only be achieved with a parallel increase in shares of shared mobility services. "If, for example, demand for shared mobility services such as ride sharing increases with new door-to-door solutions with driverless vehicles, automation can add to the overall efficiency of the overall transport system," researchers say. In particular, autonomous vehicle systems could help bring urban, shared concepts further into the mass market, as the Springer authors of the chapter Explain Success Factors for Future Business Models of Urban Shared Mobility Services from the book Mobility and Digital Transformation. However, according to the Fraunhofer researchers, it should be ensured that traffic does not shift from public to individual traffic due to the advantages of automation - because then the additional journeys could superimpose the positive effect of the savings effects. This rebound effect should be avoided.

Even if autonomous cars promise a lot of positives, they are obviously not the only answer to the ecological question of our time. Climate change will force people to use resources more sparingly than before. Planning, management and well-designed regulations are essential to reduce vehicle emissions and avoid additional vehicle mileage. Two major changes are imminent - automation and mobility as a service. Depending on how they interact and how clean the drive is, it could end up being better or worse for the environment.