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Giovanni Circella University of California Davis and Scott Hardman University of California Davis
(THE CONVERSATION.) Self-driving car technology has been elusively on the horizon for years. Despite bold predictions, fully automated cars have yet to be seen in showrooms. However, technology looks poised to take a leap in 2022.
Mercedes-Benz, BMW, and Honda have introduced so-called Level 3 Autopilots (AVs) to the market. These AVs will allow drivers to take control of the vehicle under certain conditions. Virtually every major automaker is currently testing self-driving systems.
Automated cars hold great promise. Automated vehicles have great potential to be safer than human drivers, more efficient, and offer new opportunities for seniors, disabled people, and others who are unable to drive. While safety has been the main focus, environmental impacts of automated cars have been largely ignored.
We analyze automated vehicle technologies to determine how consumers might use them. Our research teams discovered two innovative ways to assess the environmental impacts of automated vehicles in two recent studies.
We found that drivers will drive more if they have access to partially automated vehicles. This will increase transportation-related pollution and traffic congestion, unless regulators take steps to make car travel less appealing.
More miles equals more carbon emissions
Research has shown that automated vehicles could make people drive more than they do now, which could lead to more congestion, more energy consumption, and more pollution. A passenger riding in a car is less stressful than driving. People may be willing to take longer trips and fight more traffic if they have the opportunity to relax and do other things along the way. People could move further away from their jobs if they have a comfortable commute to work. This could help accelerate the growth of suburban sprawl.
People would also be able send their cars on zero-occupancy trips or to run errands alone. You might find it convenient to have your car returned home while you’re at work, so you can park it downtown and get it back when you need. Convenient, but twice as much driving.
This could pose a serious problem. Already, the transportation sector is the largest contributor to U.S. greenhouse gases emissions. California and other states that have aggressively fought climate change have realized that reducing vehicle miles is a crucial strategy. What if automated vehicle technology makes these goals more difficult?
The real-world environmental effects of automated cars
Although we and other researchers have predicted these outcomes using modeling, no one has been in a position to verify them. Fully automated vehicles aren’t yet commercially available. Two innovative methods were found to examine the real-world impact of automated vehicles.
We surveyed 940 people who drove partially automated vehicles in a study published mid-2021. While systems such as Teslas Autopilot can assist in driving tasks and reduce driving burden, it is less than fully automated vehicles.
Autopilot users drove on average nearly 5,000 miles per year, compared to those who did not use it. Interviews with 36 semi-automated car drivers revealed that they were more willing and able to drive longer distances and sat more in traffic because they have experienced less stress.
We also conducted a separate study in late 2019/early 2020. We provided 43 households in Sacramento, California with a chauffeur service that would take over driving duties, and tracked how they used it. These households traveled 60% more than their pre-chauffeur travel and used significantly less transit, bicycling, and walking. More than half the increase in vehicle travel was due to chauffeurs taking zero-occupancy trips, without any household members.
Automated car use can be a major pollutant.
These results show that partially-automated vehicles are driving more now than they were in the past. Is there a way to reap the benefits of automated vehicles without making congestion, climate change, and air quality worse?
It can be a huge help to require future automated vehicles use zero-emission technology as California is doing. However, electric cars will still produce some upstream emissions from power production until the United States develops a carbon-free electricity system. All car travel has other harmful effects, including water and air pollution, tire wear, collisions and wildlife, and congestion.
To stop an explosion in driving and the associated harms, regulators need to signal to communities that driving isn’t free. They could put a price on car travel, especially on zero-occupancy trips.
Federal and state fuel taxes are the main policy that has this effect. They currently average about 49 cents per gallons for gasoline and 55 for diesel fuel. With the widespread adoption of electric vehicles, the impact of fuel taxes will decrease on drivers behavior. This means that the transportation industry will need to create new funding mechanisms for ongoing expenses like road maintenance.
State and federal governments could introduce user fees or charges to pay for the number of miles drivers drive instead of fuel taxes. Correctly pricing private vehicle travel can encourage travelers to look into other, more cost-effective modes of transportation such as walking and biking.
These fees can be adjusted based on location, such as charging more to drive into densely populated areas or other factors like time of day, traffic congestion levels and vehicle occupancy. Modern communication technologies allow for such policies by tracking the location and time of cars on the roads.
Another option is to promote shared vehicles and not private-owned ones. These vehicles can be seen as commercial companies, similar in concept to Uber, Lyft or other ride-sharing companies. A car that is available at all times could allow you to avoid car ownership. It could also make it easier to serve travel demand by acting as on-demand transportation. These networks could also be used to help riders access fixed-route public transport services that operate along main transportation corridors.
These policies will be most effective when they are implemented now before automated vehicles become widespread. Although a future in transportation that is automated, electric, and shared could be sustainable, it is unlikely that it will happen by itself.
[Understand new developments in science, health and technology, each week. Subscribe to The Conversations science newsletter.]This article was republished by The Conversation under a Creative Commons licence. You can read the original article here. https://theconversation.com/driverless-cars-wont-be-good-for-the-environment-if-they-lead-to-more-auto-use-173819.
