(The Conversation) is an independent, non-profit source for news, analysis, and commentary from academics.
Giovanni Circella University of California Davis and Scott Hardman University of California Davis
(THE CONVERSATION.) For many years, self-driving cars technology has seemed far off the horizon. Bold predictions aside fully automated cars have yet to appear in showrooms. The technology is poised to make a big leap forward 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. Autonomous vehicles that can handle most or all of the driving duties could be safer than human drivers and more efficient. They also offer opportunities for seniors, those with disabilities, and other people who can’t drive. Although safety is the primary concern, environmental impact of automated vehicles has been neglected.
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 were able to analyze the driving habits of partially-automated vehicles and simulate the impact of future driverless vehicles. Our results showed that both types of automated vehicles will encourage more driving. This will increase transportation-related pollution and traffic congestion, unless regulators take steps to make car travel less appealing.
More miles means more carbon emissions
Research has suggested that automated vehicles might cause people to drive more than usual, increasing congestion, energy consumption, and pollution. A passenger riding in a car is much more relaxing than driving. People may be more willing to endure 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. It’s convenient, but twice as much driving.
This could be a problem. Already, the transportation sector is the main contributor to U.S. emissions of greenhouse gasses. California, for example, has made it clear that reducing the number miles traveled by vehicles is an important strategy to combat climate change. 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. Although systems like Teslas Autopilot are more capable of automating driving tasks, they can also reduce driving fatigue.
Autopilot users drove on average nearly 5,000 miles per year, compared to those who did not use it. Interviews with 36 semi-automated vehicle drivers revealed that they were more comfortable sitting in traffic and drove more long-distance trips because of the reduced stress and increased comfort.
We conducted another study in late 2019, and early 2020. We provided 43 households with a chauffeur service in Sacramento, California to simulate the operation of a fully-automated vehicle. We tracked how they used the vehicle. These households saw a 60% increase of vehicle miles and reduced use of walking, bicycling, and transit compared to before the chauffeur service. More than half of the increase was due to chauffeurs traveling on zero-occupancy trips with no household member.
Automated car use can be a major pollutant.
These findings indicate that automated vehicles will encourage more driving in future and that some partially automated vehicles are already doing so. Is there a way to reap the benefits of automated vehicles without making congestion, climate change, and air quality worse?
California is requiring future automated vehicles to use zero emission technology. This can be a great help. 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 prevent an increase in driving and other harms, regulators and communities must send signals that driving is not 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. The adoption and widespread use of electric vehicles will reduce the impact of fuel tax 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 travel. Correctly pricing private vehicle travel can encourage travelers to look into other, more cost-effective modes of travel, such as walking and bicycling.
These fees could be adjusted depending on where they are located. For example, you might charge more to drive in dense cities centers. Other factors include time of day and traffic congestion levels. Vehicle occupancy and vehicle type may also be considered. Modern communication technology can track where and when cars are driving on the roads to enable such policies.
Another option is to promote shared fleets rather than privately-owned automated vehicles. These vehicles could be viewed as commercial companies similar to Uber, Lyft, and other ride-sharing services. It could be possible to have a car on demand and serve travel demand more efficiently. These networks could also be used to help riders access fixed-route public transport services that operate along main transportation corridors.
All of these policies are most effective if adopted before automated vehicles become commonplace. 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 is republished under Creative Commons license from The Conversation. 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.
