A study says a future with driverless vehicles could make traffic congestion disappear — or exacerbate it — depending on the decisions the Washington region’s leaders make now. (Sarah L. Voisin/The Washington Post)

The one thing that’s certain about the autonomous future heralded by executives in Detroit and Silicon Valley, a future that’s either years or decades away depending on which experts you consult: It will entail more driving.

By the year 2040, the nation’s capital could be a bustling network of autonomous vehicles, with better access to jobs on its eastern and western extremities. Traffic would glide smoothly on freeways — the cars automatically keeping a safe distance by “talking” to one another — with no empty seats in the roving fleet of vehicles. The system would complement a healthy Metro that shuttles passengers between commuting hubs in the District, Maryland and Virginia.

Under another scenario, however, bumper-to-bumper traffic stretches for miles and hits the poorest neighborhoods and communities of color hardest. More people opt for the seeming comfort of a solo car ride even if it takes them longer. Low-income neighborhoods and communities of color are left in a cloud of vehicle emissions. And Metro, with the sudden shift toward cheap car commuting further depleting its ridership base, is a system on the brink.

It’s a “tale of two cities” scenario that researchers fear is already coming true with the rise of ride-hailing services, which have cut into Metro ridership, and would accelerate if autonomous vehicles allow the companies to eliminate drivers — making rides even cheaper.

“In our worst-case scenario, we see a decline in ridership on transit because people are switching their mode from transit to autonomous vehicles,” said Richard Ezike, mobility and equity fellow with the Union of Concerned Scientists, who led the study about autonomous vehicles’ impact on the region.

“We’re concerned about seeing sprawl increase, and of course that’s going to encourage more driving and take people away from transit,” Ezike said. “We definitely could see a situation where transit is basically replaced and ignored by [autonomous vehicles], so we’re very concerned about that.”


D.C. Mayor Muriel E. Bowser (D) appears with Ford executives to discuss a planned driverless car pilot and job training efforts in the District during an October news conference. (Michael Laris/The Washington Post)

The nonprofit environmental group conducted the February study that found autonomous vehicles could expand accessibility to jobs in the region, bridging the East-West opportunity divide, or exacerbate congestion and deepen existing inequalities. The group analyzed the impacts of the deployment of autonomous vehicles in the region, using a travel-demand simulation from the National Capital Region Transportation Planning Board.

“The transportation system has a lot of inequities, and [autonomous vehicles], if implemented in a way that puts the consumer they serve first, then it may improve [accessibility],” Ezike said. “But we also know those inequities can be exacerbated if we go business as usual.”

The analysts’ definition of business as usual: prioritizing driving and road construction, failing to provide adequate transit service to get people out of their cars, and neglecting to enact measures such as congestion pricing aimed at reducing traffic.

“We wanted to make sure that we made [people] aware of both sides and encouraged policymakers in the area based on the recommendation to go in a certain direction that could provide the most benefit.”

Predicting the future, however, is a difficult undertaking, and experts are growing increasingly wary of speculation about autonomous vehicles. William Riggs, an expert on self-driving cars and smart transportation and an assistant professor at the University of San Francisco School of Management, said he takes any such scenarios — bad or good — with a grain of salt. Existing travel-demand models, he said, don’t take into account potential future shifts toward car-free downtowns, differences in travel behavior such as more walking and biking or other unanticipated trends in land use and market demands.

“A lot of this is based on existing assumptions of travel behavior, which we can’t assume will be the same in an autonomous future,” he said. “The caution is that we don’t overstate the doom that AVs will cause to society and then therefore undersell the potential benefit in terms of trip optimization and saved lives.”

Riggs said the speculation around autonomous vehicles is similar to mid-20th century predictions of the future.

“We’re at the place where people in the ’50s were talking about lunar colonies,” he said.

The UCS study, performed in conjunction with transportation consultants Fehr and Peers D.C., contends that autonomous vehicles will increase driving in the region by as much as 66 percent. Efforts to pool rides and make transit investments could cut that number to 46 percent, the study says. Still, there’s another potential downside, according to the research.

“In the absence of a rapid transition to electric vehicles (EVs), this increased driving will exacerbate global warming,” it concludes. The impacts were expected to be most dramatic on low-income neighborhoods and communities of color, where congestion was projected to increase as much as six to 12 times because of their proximity to interstate highways and thoroughfares such as New York Avenue and because autonomous vehicles would fill existing transit gaps, provided the services were priced for the masses.

The result could be expanded access to opportunity — more than doubling the number of jobs accessible within 45 minutes — or, in one scenario, “increased congestion [leading] to a loss of 80 percent of this benefit if AVs were not pooled.”

The study highlighted the examples of Dumfries, in Prince William County, and Damascus, in upper Montgomery County — both of which lie on the region’s perimeter — as potential epicenters of the trends. Both are car-centric communities with limited transit access, but while Dumfries is near Interstate 95, Damascus is more isolated.

The autonomous vehicle scenarios show a “significant increase in congested [vehicle miles traveled] for Dumfries — almost 25 times the 2040 regional average — because of its location on a major regional highway,” the study says. “Because Damascus is farther from major highways, AVs cause much less local congestion.”

In the District, Anacostia and Cleveland Park served as another example of potential changes brought by autonomous vehicles. Both are within miles of the downtown core and have Metro stops, but they are starkly different demographic portraits. People of color make up 98 percent of Anacostia’s population, the study said, while Cleveland Park is 87 percent white — the former with an average household income of $23,700 and the latter at nearly $90,000.

Anacostia has less access to jobs — probably owing to the concentration of employment in the region’s western ends. High-occupancy autonomous vehicles, the research says, could serve to bridge that gap.

“Overall,” the study said, “enhancements to the transit system could increase job accessibility by transit by 126 percent and reduce the disparity in accessibility between these neighborhoods. Because transit is likely to remain the least expensive transportation option, it is especially important to enhance accessibility for low-income and other ­transit-dependent communities.”

So how can the worst-case scenario outlined in the report be averted?

For one, the researchers said, more and better transit must become increasingly competitive with car commuting. Express lanes for higher-capacity vehicles, first-mile-last-mile programs to encourage transit use and regulations requiring autonomous vehicles and fleets to be electric also are necessary. Further, the analysis recommends commencing a dialogue with those who would be most affected to convey the risks and address their potential needs in a future with autonomous vehicles.

“I would just say that it’s really important that we engage these communities that we’re talking about in the process,” said Jesse Cohn, senior transportation planner with Fehr and Peers D.C. “This was a technical research-driven report, but as we think about policies and programs to actually implement autonomous vehicles, we should make sure that people in the room are reflective of the community at large.”

The authors said those discussions about policy solutions should happen sooner rather than later, contending that the shift toward driverless cars is already beginning. Ford announced in the fall that it plans to launch an autonomous ride-hailing service in Washington by 2021.

“AVs are already here — companies such as Waymo, Uber, Lyft, and Ford are actively testing them on streets today — and they may be common within the next few years,” the study says. “Now is the time for citizens and policymakers to start planning the cities and regions that will meet their needs, not just benefit the AV companies.”

Greg Rogers, director of government affairs and mobility innovation for the nonprofit Securing America’s Future Energy, said many of the prescribed actions can and should be taken now — regardless of the implications of autonomous vehicles. He said in every case — autonomy, electrification, more travel through ride-hailing — the eventual outcome is always still “rubber on the road.”

“We don’t even know how AVs are going to be used — they could be used in buses, they could be used in regular cars, the shape of our cars might even change,” said Rogers, whose group aims to reduce the nation’s dependence on oil. “But the fact is that everything we can do to prepare for the potential negative impacts of AVs we can be doing today.”