Self-driving cars are the future. But exactly what that future will look like is still to be determined.
What is more certain is that California will play an outsize role in shaping our transportation future. Our state is at the epicenter of automated driving technology development. It is also a pioneer in tackling climate change at the gas pump, through our Low Carbon Fuel Standard and the Zero-Emission Vehicle program. California is ideally positioned to show the world how a driverless transportation future could help clean the air and cut greenhouse gas emissions. Without this kind of leadership, driverless vehicles could end up doing a lot of environmental damage.
The 3 Revolutions Policy Initiative at the Institute of Transportation Studies of the University of California Davis recently released a policy brief on Keeping Vehicle Use and Greenhouse Gas Emissions in Check in a Driverless Vehicle World. It highlights the actions policymakers can take to ensure the automated vehicle revolution goes easy on the Earth.
The 3 Revolutions policy brief focuses on two measures of potential trouble: vehicle miles traveled (VMT) and greenhouse gas (GHG) emissions. If everyone simply switches from traditional cars to driverless vehicles, both VMT and GHG can be expected to rise. That’s because driverless cars are expected to make travel cheaper and dramatically more convenient: among other predicted impacts of AVs, people will no longer feel stuck behind the wheel, but will be able to spend travel time working, resting, or entertaining themselves with screens or hobbies instead. They might even decide to live further away from their jobs, where land is cheap and housing units bigger, as commuting in traffic would not be perceived a strong deterrent.
A suite of strategies can help keep greenhouse gas emissions and vehicle miles traveled in check, even as driverless vehicles take over the road. Among others, these include:
- Deploying driverless cars as shared-use vehiclesrather than privately-owned (and used) transportation options. Sharing vehicles through transportation companies or public agencies would remove the sunk costs of auto ownership and transfer the transportation cost to per-mile share of expenses. This would mitigate the increase in VMT. Sharing cars would also reduce the time cars sit idling in a driveway (or garage) and free up parking space for infill development.
- Ensuring widespread carpooling.If passengers are willing to share a ride to the same destination, this would decrease total VMT while providing mobility options to individuals. But travelers often don’t want to share. And the land use of many cities and regions is simply not conducive to carpooling, as origins and destinations are too far from each other. Pricing tools should be used to encourage shared use of vehicles rather than “riding alone”.
- Coordinating AV shared vehicleswith transit could cut travel costs significantly and reduce VMT and GHG emissions through providing the first/last mile access to high-quality public transportation. But this isn’t likely to happen without incentives that encourage it.
- Deploying driverless vehicles as zero-emission vehicles. Automated vehicles powered by electricity or other zero-tailpipe-emission sources of energy would help curb GHG emissions (assuming electricity is not produced burning coal).
- Introducing pricing. Charging travelers to use roads and curb space could be used strategically to boost carpooling and transit use, shift trips to less-congested times of the day, discourage travel by empty driverless vehicles, and accomplish other transportation goals.
- Increasing high-quality and high-density transit. On main corridors in high-density areas, mass transit will remain the most efficient way to move people. Driverless cars could improve first- and last-mile connections to subways, buses and other transit options, expanding ridership (see the previous bullet on the coordination of shared AVs with transit).
- Ensuring driverless vehicles are not larger or more energy consumptive. Automation might lead to big changes in vehicle design, especially if a front-facing driver is not required anymore. The shape and design of vehicles could change dramatically. This could lead to giant vehicles housing exercise equipment, kitchens, dining rooms, offices or other facilities, which could increase energy use and emissions and slow traffic.
- Programming vehicles to improve livability, safety and comfort on surface streets. The National Association of City Transportation Officials advocates a 25 MPH speed limit on urban streets for driverless cars, in order to reduce pedestrian and bicyclist fatalities. Improving the safety of roadways will encourage more bike and pedestrian travel, and ensure that driverless cars complement, and do not substitute, active transportation.
As we cruise towards a future in which traveling by car doesn’t require constantly paying attention to the road, we must continually improve our understanding of what driverless cars mean for our society and how policy decisions can steer automated transportation in the right direction.
Driverless transportation could usher in an era of better, safer, more affordable mobility while keeping air quality and climate change in check. But we can’t expect all those good things to happen by accident. It will take California’s leadership to set an example of decisive and sustainable action.