opinion

Self-driving cars will not be Nashville's transit savior

A few voices critical of Mayor Megan Barry’s plan to develop an extensive high-capacity transit system in Nashville say investing in light rail and additional buses is unneeded because driverless cars are supposed to be in operation today in other places.

Metro Councilmember Robert Swope has repeatedly offered a vision of “autonomous vehicle systems that will replace the need for large, costly mass transportation.” Vanderbilt professor Malcolm Getz similarly argues “Nashville’s future should be oriented towards express lanes for autonomous vehicles, not towards building trains.”

This vision is being offered sporadically around the country, and is largely fueled by hype emanating from Silicon Valley and Detroit. But its logic fails in basic ways regarding timing, transportation and technology.

Techno-optimism or utopianism has its attractions, but is speculative at best and, if paid too much heed, can create harmful distortions in policy debates over real-world problems and solutions.

The assertion that autonomous vehicles are in practical operation is wrong. “Autonomous” vehicles being tested today in real urban environments require human drivers to continuously intervene. Sober estimates of truly driverless vehicle operation in cities range from a sunny 2025 for taxi-like fleets on pre-defined routes to never, and in all cases constitute speculation facing big unknowns.

Beyond technology, fundamental questions of driverless car cost, business models, fleet operations, market penetration and more have yet to be significantly addressed.

But say the dream of fleets of roaming robot taxis and vans does someday arrive, and makes economic sense for operators and commuters. It won’t change the fact that cars hog space, whether they are Lyft, Uber, electric or driverless.

Technology, venture capital and breathless conference presentations can’t change the basic fact of geometry that 60 people in cars take up far, far more space than 60 people in a bus. When one considers the thousands of passengers per hour light rail lines can move in very little space, it’s not difficult to see why Mayor Barry sees transit as the key to continued growth in Nashville. Transit will always be far and away the most space-efficient way of moving people.

Allowing many people to coexist and move within a small area is what makes cities succeed and thrive. But a city can’t efficiently fill skyscrapers with people each morning by having everyone try to drive into downtown at the same time, even if in theory they may one day arrive with a couple of fellow passengers in a pooled robo-car.

Nashville will certainly face challenges on its way to becoming a transit-oriented city. Transit attracts far more riders when people can walk to it, and Nashville needs a lot of work to become more pedestrian-friendly.

Mayor Barry’s policies, budgets and agency reforms recognize this issue. There is time to build sidewalks and safer intersections as the transit plan unfolds, and these will bring additional benefits and value to the city’s commercial districts and neighborhoods. Nashville also needs to build a stronger bus system to build transit usage during the planning and construction lead times required to implement rail, and to allow more people to connect to rail and access areas rail does not reach. The set of projects and improvements for funding that the Mayor released last week, and the regional nMotion plan both account for this.

At TransitCenter, we track transit policies and performance around the United States and across the world -- the good, the bad and the ugly. It’s rare to see a city approach transit development with a set of supporting policies and programs as well developed and thought-through as those Nashville has created under Mayor Barry. Her transit plan is right for Nashville, and we strongly urge the people, civic and business leaders and elected officials of your city to back it fully.

Hayley Richardson and Jon Orcutt are the communications team for TransitCenter, a national foundation dedicated to improving public transit.