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Could Autonomous Vehicles Add to Congestion? Maybe, Say Planners

The topic of how to plan for autonomous vehicle deployment and use is beginning to come to the forefront for city planners in jurisdictions of all sizes.

The car-riding public may not be the only ones with self-driving car jitters these days. City planners — those people who set public policy around how our cities develop — are also raising questions about what autonomous vehicles could mean for parking, traffic and other perennial urban development issues.

“Many planners speculate that since autonomous car occupants no longer need to waste the time spent in their vehicles, they may drive more miles,” said William W. Riggs, a professor of management at the University of San Francisco who focuses on city planning and transportation. 

“This could have the adverse impact of expanding cities beyond their existing boundaries, gobbling up open spaces, moving people away from downtown areas which are rich in commerce and culture and heightening socio-economic divides,” said Riggs in an interview with Government Technology following the 2018 National Planning Conference last month, where Riggs participated in a panel discussion about what AVs could mean for the future of cities.

Cities across the country have adopted development philosophies that translate into denser, more mixed-use living, where cycling and public transit start to take priority over cars in an aim to reduce both traffic congestion and greenhouse gases. These efforts have been borne out in the form of new streetcar and light rail lines, bike lanes, auto-charging ports and policies and infrastructure to support a city environment that’s a little less car-filled and car-dependent.

The concern, say planners, is autonomous vehicles could transform today’s world of privately-owned vehicles into one where residents use shared autonomous vehicles — known as “Mobility as a Service” (MaaS) — placing lots of cars in constant circulation on roadways. It’s a scenario not entirely unlike current concerns around transportation network companies (TNCs) like Uber or Lyft filling many downtown streets.

“The impact [TNCs] have on travel behavior and congestion are likely harbingers of behavior in the AV future — absent policy, of course,” said Riggs.

It’s not just urban areas that planners will have to consider when carving out public policy around AVs, and some of the technologies are finding their way into highway design. 

“Autonomous vehicles will affect that clear-line-of-sight triangle and will end up affecting what you have in your fence regulations down the road,” said Jennifer Henaghan, the deputy research director and Green Communities Center manager at the American Planning Association.

“This really is an issue that planners need to start thinking about. And not just those planners who are the head of a huge metropolitan planning organization, but planners in every town — big town, small town, urban, rural — it’s going to affect everyone. So that’s why we need to start talking about it,” said Henaghan, during a Feb. 26 APA podcast titled Planning the Autonomous Future.

The issue is real, say those in the autonomous vehicle and planning circles — as most estimates show a number of car companies are set to unveil a range of AV-enabled cars in the next three to five years. However, a full-scale adoption and use by the American public could be decades away, said Kelley Coyner, CEO of Mobility e3, a transportation company that helps communities plan, pilot and deploy AV fleets.

The U.S. market is probably five or six years away from even a limited release of fully autonomous vehicles, said Coyner.

“And then more like 25 or 30 years before you see a huge deployment of those kinds of vehicles,” she said during the APA podcast.

However, if AVs are to expand the concept of mobility as a service, cities ought to prepare for much emptier parking lots, garages and street-side parking, say planners.

“Most indications are that parking demand will decrease and that most vehicles will be shared, at least in the near term,” said Riggs. “We are already seeing decreased parking demand in cities due to Uber and Lyft.”

If parking spaces are to sit empty, then cities should begin to give more thought into how right-of-way space is managed, said Riggs.

“I call this just good planning,” he remarked. “AVs provide an opportunity to reinvent the space on streets. If you gain some efficiency and don’t need to park vehicles, then what can and should happen with that space? I believe it should be prioritized for pedestrians, bikes, transit or even more housing.”

Cities around the country are zeroing in on this space, say others who study urban systems and smart city initiatives.

“Many of the conversations we’ve heard around the country and initial pilots are focused on ride-sourcing in heavy traffic areas,” said Russ Brooks, smart cities director at Transportation for America, an alliance of civic, business and elected officials advocating for smart transportation and smart city projects. “But, given the increasing demand for that real estate, we want to make sure that we’re including every use case and user as part of our conversations whether that be paratransit, ride-hailing, micro-transit, AVs or urban delivery in all its forms.”

Some of the traffic-controlling methods cities are exploring involve programs known as “congestion-pricing,” where cars pay extra to enter a high-traffic urban area. New York lawmakers walked away from that idea last month, despite strong support by Gov. Andrew Cuomo. It’s an idea that should get another look, said Riggs.

“Cities, regions and states also need to be considering new pricing and behavioral incentive programs. This includes exploring more robust congestion pricing and or vehicle-miles travel fees,” he said. “It also means designing programs that focus on creating a culture that’s about sustainable travel.”

Skip Descant writes about smart cities, the Internet of Things, transportation and other areas. He spent more than 12 years reporting for daily newspapers in Mississippi, Arkansas, Louisiana and California. He lives in downtown Sacramento.

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