Nashville transit referendum: Where do Uber, Lyft, autonomous vehicles fit in?

As the vote on Nashville transit approaches, opponents are suggesting alternatives to the multi-billion dollar plan that includes light rail, rapid bus transit and a downtown tunnel.

The alternatives range from van ride-sharing, subsidized ride-sharing for low-income residents and focusing on self-driving cars.

The ideas reflect a common complaint from opponents of the transit plan, that it relies heavily on old technology and does not adequately incorporate the advancements being made in ride-sharing, autonomous vehicles or, even, flying taxis.

"If we are having revolutionary technologies that are going to likely be in play in the next 20 (years), why would we invest $9 billion in a system that is very unlikely to to be utilized because of more viable alternatives?" said John Maddox, who is promoting van ride-sharing as an alternative to the transit plan.

Erin Hafkenschiel, director of Mayor David Briley's Office of Transportation and Sustainability, said opponents' characterization of the Let's Move Nashville plan as relying on on "19th-century" solutions is false.

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While there is not a specific line item for "technology," the latest technology is part of each component, including light rail, rapid bus service and ride-sharing, she said.

The plan includes Lyft and Uber as a way of getting commuters to and from public transportation, and autonomous vehicles are mentioned as part of a transit system that "embraces paradigm-shifting technology."

Hafkenschiel said ride-sharing is also targeted as a solution for areas where fixed routes don't make sense. As self-driving cars are introduced, they will be integrated as well.

While these technologies can enhance transit systems, they will not solve problems by themselves, she said.

"Because an autonomous vehicle is still a car, regardless whether it's driven by a ride-share driver or by a computer, they still take up quite a bit of space," Hafkenschiel said. "When you're looking at our most congested areas and corridors, it's not going to be the most effective way to move people."

Daniel Work, a civil engineering associate professor at Vanderbilt University who has endorsed the Nashville plan, said automated and connected vehicles could as much as triple road capacity if cars are traveling close together at high speeds and are programmed to communicate with the same language.

But, like Hafkenschiel, he does not see them as a congestion remedy because of the physical space they consume.

"No matter how many clever things we do with technology and automation, there is a limit on how many cars per hour can pass a point on a roadway," he said. "Buses or other public transit infrastructure is a way to get insane capacity compared to cars."

The self-driving car debate

Work also cautioned that self-driving cars could lead to less road capacity if the car experience improves. He described preliminary studies in which chauffeured driving led to significantly more car trips.

“If you make driving less painful, people will drive more,” Work said. “If you add autonomous vehicles and we as residents choose to drive more, that will increase vehicle miles traveled. Even if there are capacity benefits from this technology, the fact that we demand more travel may offset those potential benefits on capacity."

Lewis Fulton, who teaches at the Institute of Transportation Studies at the University of California, Davis, said over time, driverless cars could take cities in two different directions: either making residents less reliant on automobiles or reinforcing their dependence.

If individuals see them as a part of a shared fleet that can take them to their destination, or to public transportation options, the attachment to personalized vehicles could wane and traffic could decrease. But, if individuals use personal self-driving cars to get to their destinations, traffic could worsen.

“Governments and citizens can really influence where this goes,” Fulton said. “There could be policies that discourage people from using automated vehicles as their own household vehicles.”

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Only so much road capacity

Brown University economics Professor Matthew Turner points to Los Angeles as an example of increased road capacity failing to solve congestion problems. As highways expanded, they simply filled with more vehicles.

"As you increase capacity, the demand to use the road increases in lockstep," Turner said. "Whatever benefits these ridesharing technologies may bring, I would not expect a dramatic reduction in congestion."

Turner said the most meaningful improvement to traffic could come through pricing. Nashville has a congestion problem at peak hours but not at other times, he said. Ride-sharing apps and driverless cars could bring with them the technology to charge commuters who travel during peak hours and alter congestion patterns.

"That will provide people with an incentive to use the capacity you have at off-peak times and then you don't have to build anything else," Turner said. "With self-driving cars, it's really easy to do. You are already paying for the mile and for surge pricing... Because it’s a new way of paying for things, it's an opportunity to put these kind of pricing programs in place."

Metro Councilman Robert Swope is opposed to the Let's Move Nashville plan primarily because of the fixed nature of light rail that does not easily adapt to geographic shifts in population.

He has long advocated for a solution of incorporating self-driving vehicles and is proposing an alternative plan Tuesday. He said he prefers "a system that is completely mobile," and that could be changed "with a push of a button depending on need and demand."

The timeline of autonomous vehicles

A key hurdle prevents the implementation of driverless cars: they are not yet ready for use. Some companies forecast they will have autonomous vehicles ready for deployment by 2020, but when they will be part of mainstream transportation is unclear.

Two recent fatalities caused by self-driving vehicles operated by Uber and Tesla have further complicated timelines. Uber has stalled self-driving tests and Arizona suspended Uber's testing in the state.

"There is a transition here that is going to take time and it's probably going to be a fairly long period where you have both driverless cars and driven cars," Fulton said. "That might mean we are well past 2030 before we really are in that world where that’s ubiquitous, where it's normal that people are riding around in driverless cars."

In 2016, Nashville was chosen as one of 10 global cities for an autonomous vehicles initiative launched by Bloomberg Philanthropies and the Aspen Institute. At the initiative's three events in 2017, Hafkenschiel said she repeatedly pressed industry leaders about whether investments in light rail and rapid bus transit were viable in an autonomous vehicle environment.

"Over and over again, people said 'Yes, absolutely,'" she said.

Nashville also has encouraged automakers to use the city as a testing ground for driverless cars, she said.

"We want to work with them," Hafkenschiel said. "We think it's part of the solution, particularly to address more of our suburban and rural areas, but it's not a whole part of the solution."

Reach Jamie McGee at 615-259-8071 and on Twitter @JamieMcGee_.