The Answer to Seattle’s Traffic Problems? Shared Self-Driving Vehicles

This article appears in print in the September 2018 issue. Click here for a free subscription.

This summer, boston permitted the citywide expansion of a previously limited pilot program for autonomous vehicles (AVs) by MIT spinoff nuTonomy. The move was a recognition that the arrival of AVs is happening a lot faster than anyone expected, and that the technology offers the potential not only for reduced traffic fatalities but also to reduce the number of vehicles on our roadways through the adoption of shared fleets of autonomous vehicles.

Our East Coast counterpart has the right idea. Because if AVs are single occupancy, and people take advantage of their capabilities to buy homes in distant suburbs and exurbs, and then sleep as their cars drive them to work, the result will be nightmarish congestion.

But if we can take advantage of the expected lower cost of operating self-driving vans and cars to supplement our public transit system by connecting hubs in distant neighborhoods to light-rail and express-bus stations, the AV revolution could go a long way toward reducing congestion. A 2017 report by the Seattle Department of Transportation concluded that autonomous vehicles, if shared rather than devoted to single occupancy, would result in 45 percent fewer cars in Seattle by 2030.

Widespread use of AVs is years away, but its an issue we need to consider today because many of the changes needed to take advantage of the revolutionary vehicles should inform the decisions we make as we undertake a costly transformation of our citys infrastructure. Spaces that robotaxis of the future will need to drop off passengers, for example, would also be helpful today to let Uber and Lyft drivers drop off passengers without stopping traffic. Seattles decision to allow less parking downtown, while widely criticized, looks smart in light of the reduced number of vehicles we will see in the age of AVs.

In Reshaping Urban Mobility with Autonomous Vehicles: Lessons from the City of Boston, the Boston Consulting Group predicts that demand for parking in Boston will drop by 48 percent as AVs come into general use. Some architects are designing the parking levels in new buildings so these areas can later be converted to office space or other uses when demand for parking falls.

Seattle Mayor Jenny Durkans proposal earlier this year to consider congestion pricing also looks smart in this approaching brave new world. A London-style system that charges vehicles going to and from the city would reduce congestion today by encouraging more people to take public transit. The same approach, perhaps modified in the future to also allow for charging fees based on time and distance traveled, as well as the number of occupants in a vehicle, would discourage the future use of single-occupancy AVs while encouraging the use of self-driving vans and robotaxis transporting large numbers of people on set routes.

If the same policies that will lead to sensible use of AVs in the future also help us address the congestion we face today, whats not to like?