Autonomous vehicles could usher in a new era of pedestrian supremacy.

New research carried out by Adam Millard-Ball, assistant professor of environmental studies at the University of California, Santa Cruz, uses game theory to analyze the interactions between pedestrians and self-driving vehicles, with a focus on yielding at crosswalks. Because autonomous vehicles are by design risk-averse, his model suggests that pedestrians will be able to act with impunity, and he thinks autonomous vehicles may facilitate a shift toward pedestrian-oriented urban neighborhoods.

Planners could seize on the opportunity provided by autonomous cars to create more pedestrian-oriented streets. Image credit: Pixabay.“Pedestrians routinely play the game of chicken,” Millard-Ball says. Crossing the street, even at a marked crosswalk without a traffic signal, “requires an implicit, instantaneous probability calculation: what are the odds of survival?”

Self-driving cars are programmed to obey the rules of the road, including waiting for pedestrians to cross. Secure in the knowledge that a car will yield, pedestrians merely need to act unpredictably or step into the street to force the risk-averse car to stop.

Millard-Ball suggests that the potential benefits of self-driving cars—avoiding the tedium of traffic and the trauma of collisions—may actually be outweighed by the drawbacks of an always-play-it-safe vehicle that slows traffic for everybody. As such, autonomous cars' strategic disadvantage in slowing down urban traffic could hamper their adoption, he suggests.

“From the point of view of a passenger in an automated car, it would be like driving down a street filled with unaccompanied five-year-old children,” he says.

As a result, planners and policymakers have an important role to play in shaping the impact of autonomous vehicles to benefit urban society, Millard-Ball says. One approach would be to maintain traffic speeds by eliminating crosswalks, erecting fences between the sidewalk and roadway to corral pedestrians and stepping up enforcement against jaywalkers. Alternatively, planners could seize the opportunity to create more pedestrian-oriented streets and relegate drop-offs to the fringes of urban commercial districts, he says.