I’m not sure how excited to be about the likelihood of autonomous vehicles.
From a climate perspective, it is hard to know whether vehicle autonomy will help. “Autonomous Connected Electric Shared Vehicles” (ACES) may help reduce carbon emissions by accelerating adoption of electric vehicles and possibly by encouraging ride sharing. Or, self-driving vehicles may lead to more driving, including driving of traditionally-powered vehicles.
Similarly, from an equity perspective, autonomous vehicles may give people new inexpensive mobility, but they may also destroy an major job category that does not require much education.
Those with a passion for the ACES vision foresee a compelling and rapid transition, like the single-decade transition from horse carriages to cars that happened in the last century: The elimination of driver labor will lower the cost of a chauffeured ride to the point where most people will suddenly find that using “Transportation as a service” (TaaS) is both cheaper and preferable to individual car ownership. Enormous value will be created for consumers because they will not have to spend money on buying and maintaining their own car. Shared vehicles will be marketable at a higher price point, facilitating the needed transition to electric vehicles. Fleets of self-driving vehicles that can be summonsed from a smartphone will move efficiently through the streets stopping only for a rapid recharge at well-timed moments. Both cities and suburbs will become greener as parking lots become unnecessary.
I wouldn’t bet against the technology. Major automakers, as well as Google and Amazon, are pouring money into it. The prototypes are working better and better. When a model is perfected, it could be licensed to multiple automakers.
I hope I am wrong, but my instinct is that owning a personal vehicle will remain a high priority for many people even when TaaS becomes less expensive because vehicles can drive themselves.
To the extent we continue to travel daily to work and school at around the same time, we will still have a rush hour. The total vehicle fleet will continue to need to be big enough to handle all of that simultaneous demand. In other words, it will have to be almost as big as our existing collection of individually owned vehicles. At full scale, TaaS would not have a big cost advantage over private vehicle ownership.
If many more people were willing to routinely share rides, that could increase the TaaS cost advantage. Shared rides have always been encouraged as a solution to congestion. In any region at rush hour, there are thousands of people making the same trip at the same time. If they could share rides we would see a dramatic reduction in vehicles on the road. Apps can match riders more efficiently than workplace bulletin boards.
But car pooling peaked in the energy crisis of the 70s and declined as gas prices went down and private vehicle ownership has increased. People are not necessarily looking for companionship on the road. People under time pressure do not want to detour to pick up or drop off another rider. Many people use their car to store convenience items.
The limited market penetration of Uber and Lyft offer an indication of the limits of Transportation as a Service. While they have wreaked havoc on the taxi business, they accounted for only 1.3% of all passenger trips in 2019 in Massachusetts. And those were shorter trips on average, heavily concentrated in urban areas, more than half starting in Boston or Cambridge.
Use of ride service vehicles could become even less attractive without drivers. Service drivers are screened for criminal records and serve as a third party to referee disputes and oversee the interior space of a vehicle. Sharing the back seat with a random stranger is even less appealing if there is no one else in the vehicle. Remote supervision by camera could offer some assurance of safety and deter some crime, but a remote supervisor could not immediately intervene within the vehicle. And remote supervisors cannot do much about the spilled coffee and worse things that humans leave behind.
Even if private vehicle ownership persists, that does not mean that autonomous vehicles will make no difference. Autonomous vehicles that communicate with each other may be able to drive closer to one another and increase the capacity of high speed roads. (See the Governor’s Commission on the Future of Transportation, Volume II, page 64 for this point and a good overview of the autonomous vehicles.) Autonomous taxis could offer less expensive mobility options in poverty areas that are currently inadequately served.
Autonomous vehicles could help offer “last mile” connections to mass transit (although at rush hour, the simultaneous station arrivals would likely be too numerous for the shared autonomous fleet to support). For a thoughtful exploration of the impact of shared autonomous vehicles in cities that combine auto use with transit see MIT’s Insights into Future Mobility (Chapter 6); the upshot is that unless carefully coordinated with transit, they will like result in less transit use and more congestion.
Autonomous vehicles could free up the attention of drivers and allow them to safely read or converse, perhaps combining the comfort of a train ride with the privacy of a personal vehicle. Unfortunately, this could draw more longer haul commuters off of rail and contribute to congestion.
Autonomous vehicles may have a larger role to play in trucking. Autonomous vehicles do best in simpler environments like limited access highways. They could reliably handle the long-haul freeway driving, waking up the truck driver to handle the final maneuvering for delivery.
The physical measures the public sector might need to take to support autonomous vehicles are mostly the same kinds of measures we are already taking to support electric vehicle expansion (charging stations) and to support human-driven transportation network companies like Uber and Lyft (pickup locations, coordination with transit, etc.).
There are likely some regulatory changes needed to clarify rules and liability for autonomous vehicles. In 2016, the Governor signed an executive order creating an initial framework for autonomous vehicle testing and a MassDOT working group has produced a report suggesting areas for legislative adjustment.
For now, my take is that we should make the necessary adjustments to facilitate progress, but we should not expect autonomous vehicles to solve our clean energy challenges in transportation.