Watch Daniel Malarkey’s appearance on Q13’s newscast in which he discusses the future of autonomous electric vehicles.

Climate hawks know the best way to decarbonize our economy is to electrify everything, fast. But we’ve made little progress electrifying transportation, the source of over half of the carbon emissions in Oregon and Washington. Shared fleets of autonomous electric vehicles—robo-taxis—could drive us to a low-carbon future much faster than the current plodding accretion of electric vehicles among individual owners.

How slow is it? Despite all the buzz about Tesla, electric vehicles (EVs) have barely made a dent in Cascadia’s vehicle fleet. Only 20,000 out of the 4.6 million registered passenger vehicles in Washington were electric, less than half a percent. Unless something dramatic happens, the state’s existing polluting cars and trucks will remain on the roads for decades. I dug into Washington’s Department of Licensing database to estimate just how long the polluters will persist, and the data on durability is seen below.

Original Sightline Institute graphic, available under our free use policy.

Almost all cars stay on the road for at least a decade; then they start to slowly exit the fleet. At two decades, about half of vehicles are still on the road. Three decades in, the cohort finally dips below 10 percent of its original size. Even with increasingly bullish predictions on future EV sales, the durability of existing and future vehicles with internal combustion engines will retard the electrification of transportation.

Electric cars look certain to grow as a share of new car sales. The steady fall in lithium-ion battery prices and the related decreases in vehicle costs have convinced analysts that EVs will move into the mainstream. Bloomberg, for example, now predicts EVs will represent 54 percent of new car sales in 2040, up from its prior estimate of 35 percent and nearly five times other estimates of future EV penetration. If we assume a straight line increase in EV sales that hits the optimistic Bloomberg forecast, the electrification of the passenger vehicle fleet in Washington over the next 23 years will look slow as molasses, as seen below.

Original Sightline Institute graphic, available under our free use policy.

Note that 2 million cars (37 percent) that will be driving in 2030 are already on the road today. In 2030, EVs (the palest wedge atop the figure) will comprise 11 percent of the fleet and by 2040 will be less than 30 percent. And this scenario assumes one of the most optimistic forecasts of future EV sales. The transition will be slow because even with all the aforementioned decreases in the cost of privately owned electric vehicles, EVs will not be cheap enough to convince us to abandon still-operable gas cars. We’ll keep driving our gas cars until they won’t go anymore.

But if we shift our transportation consumption from individual vehicle ownership to buying transportation services from fleet providers, electrification could happen fast. Electric robo-taxis would allow people to share a fleet of vehicles and only pay for what they use, rather than the whole cost of a vehicle that sits idle and depreciating 23 hours a day.

Electric robo-taxis would allow people to share a fleet of vehicles and only pay for what they use, rather than the whole cost of a vehicle that sits idle and depreciating 23 hours a day.
Tweet This

Robo-taxi  providers will choose electric vehicles for this service, not out of concern for greenhouse gas emissions necessarily, but because electric fleet vehicles will cost less than half as much to own and operate as gasoline-powered vehicles. With high utilization inside a fleet, electric cars will likely have much lower maintenance, depreciation, and energy costs than vehicles powered by gasoline.

The cost per mile of autonomous electric transportation service when delivered in fleets with thousands of vehicles could be less than one third the current costs for auto owners who drive their own cars. The savings for consumers who shed a car and use robo-taxis instead promise to be many thousands of dollars per year—many thousands for each private car they set free. Already, Lyft and Uber are pushing up the car-free populations of Cascadia’s urban centers. When their vehicles and those of new competitors are reliably and safely self-driving, the costs will plummet and allow car ownership to go into free fall.

Tony Seba and James Arbib at ReThinkX make the case that this change could happen fast. They foresee a conversion from individual ownership to robo-taxis or what they call Transportation as a Service (TaaS) over a single decade. They have estimated the resulting reduction in petroleum consumption in the US light-vehicle fleet between 2020 and 2030. I converted their petroleum consumption forecast to millions of metric tons of carbon equivalents  and then compared the resulting TaaS forecast with a base case forecast prepared by the US Energy Information Agency as part of the 2018 Annual Energy Outlook.

Original Sightline Institute graphic, available under our free use policy.


This shows that by 2030, with rapid deployment of TaaS, carbon emissions from transportation could be one tenth of the EIA’s baseline forecast. People may not embrace TaaS as fast as Arbib and Seba think, but whatever the adoption rate, the shift to electric robo-taxis will reduce emissions far below the current trend lines.

  • Our work is made possible by the generosity of people like you!

    Thanks to Ronald & Patricia Schauer for supporting a sustainable Cascadia.

  • With smart public policy, we can mitigate the downsides and help accelerate deployment to realize the benefits as soon as possible.

    Getting the public policy right does not have to be a heavy lift politically. Climate hawks don’t need to ask for big tax increases or massive public investment; our existing road and highway networks and electric grid have enough capacity. Those concerned about greenhouse gases from transportation don’t need to advocate for regulations requiring people to sacrifice comfort or convenience. People will choose zero emission service from robo-taxi providers because it is cheaper and better than driving their old car and because it is good for the environment.

    Broadscale adoption of robo-taxis has potential downsides and represents a fundamental disruption to our transportation system but the upsides include big cuts in greenhouse emissions, improved mobility, and lower costs.
    Tweet This

    Climate hawks could offer an important voice in support of efforts to establish clear rules for existing ride-sharing companies like Uber and Lyft and their future competitors. These companies now confront inconsistent regulations across local jurisdictions that raise costs and create uncertainty. For example, Senate Bill 6043 in the Washington legislature would have taken an important step towards establishing a sensible framework that clarifies the respective roles of state and local governments in regulating Uber and Lyft.

    Climate hawks have built coalitions with labor and social justice groups to support carbon pollution pricing. Those same constituencies will care deeply about the potential job losses associated with self-driving vehicles. Their voices need to be heard on how best to mitigate those disruptions and create pathways to new employment so the benefits of this clean, new low-cost transportation mode accrue to everyone.

    Claims from auto companies about self-driving capabilities deserve some skepticism. After all, the same companies lied repeatedly about the consequences of safety and environmental regulations in the past. Volkswagen perpetrated a massive international fraud to hide the actual emissions of their diesel cars. After battling the auto industry and eventually winning on the Oregon and Washington Clean Car Laws in 2005, Cascadia’s climate hawks will want to take a careful look before making common cause with a former foe. But climate solutions can show up in surprising places, including the back seat of an autonomous electric car built and operated by General Motors.

    Our best, and perhaps only, hope to slash greenhouse gas emissions from cars and trucks in the next one to two decades is to adopt a sensible regulatory framework that enables rapid deployment of electric robo-taxis when the technology is ready.