A day after his administration asked self-driving car companies to suspend testing on Boston’s roads, Mayor Martin J. Walsh called for clear regulations to govern the fledgling technology.
But he said the pause — a response to the death of a pedestrian hit by a self-driving Uber car in Tempe, Ariz. — would probably only last “a couple of days” as city officials review the safety procedures of the two Boston companies experimenting with the vehicles, nuTonomy Inc. and Optimus Ride.
“Just to make sure the safety precautions are there,” Walsh said outside an event in Boston on Tuesday. He added that an incoming snowstorm could lengthen the interruption.
NuTonomy said it is “working with City of Boston officials to ensure that our automated vehicle pilots continue to adhere to high standards of safety” and has paused testing. Optimus Ride did not respond to requests for comment.
Walsh also said the crash in Arizona showed a need for clear rules and standards for the industry.
“We have to really think long and hard as we do more and more self-driving cars,” he said. “A lot of people realize it’s coming, self-driving cars, and now we have to make sure we put the proper procedures in place and the proper safeguards in place.”
The mayor referenced a bill that passed the US House last year that would allow more cars to be tested across the country, but it is being held up in the Senate in part because of concerns about the safety of the technology and whether it is ready to be widely deployed. Walsh did not say whether he supports that legislation.
Several bills also have been filed in the Legislature that would clearly define the rules for autonomous cars here. And a state panel established to study the technology is expected to issue its own recommendations in the near future.
Massachusetts law is notably ambiguous about the use of the technology. Current rules require all vehicles to have steering wheels and brake pads but do not specify that humans must use them.
Already, some consumer vehicles, such as Tesla cars, allow drivers to turn on a feature that will self-pilot a car on the highway. However, no autonomous car companies are known to be testing on public roads without approval from city and state officials.
Boston has become a hotbed for the technology, which advocates say could lead to far fewer driving-related deaths by taking the wheel from the hands of flawed humans.
But testing here is still relatively limited compared with that in states such as California and Arizona.
NuTonomy and Optimus Ride began testing cars in Boston last year, after Walsh and Governor Charlie Baker allowed the companies to drive in a small section of the Seaport District around the marine industrial park. They’re required to keep two employees in the vehicles at a time, including one behind the wheel who can take over control of the car.
NuTonomy has since received permission to expand testing across the Seaport and is also carting a small pool of passengers around the neighborhood through a partnership with the ride-hailing firm Lyft.
Arizona has developed a reputation as a Wild West for the technology, allowing a wider deployment for testing. The state allows self-driving cars without humans in the driver seat, though the vehicle in the crash did have an Uber employee behind the wheel.
The accident happened Sunday evening, with officials saying the Uber vehicle did not slow before hitting 49-year-old Elaine Herzberg. But the police chief in Tempe told the San Francisco Chronicle that Uber may not have been at fault in the accident because the pedestrian was not in a crosswalk but “came from the shadows right into the roadway.”
The Uber car was going about 40 miles per hour; in Boston, test vehicles must follow the speed limit of 25 miles per hour.
The local companies also had to successfully complete a first phase of testing without major incidents before being allowed to drive in nondaylight hours.
Walsh said the program in Boston is safe because the testing area is so limited. Yet that section of Boston is among the city’s most congested, with stop-and-go traffic throughout much of the day on the streets where nuTonomy is testing its cars.
While that would more likely further limit the speed of any self-driving cars, it also presents a constant stream of objects for the technology to navigate around.
Moreover, Boston is notorious for pedestrians regularly ignoring jay-walking rules and crossing streets at random and in heavy traffic.
The companies are required to file regular updates to the city about safety issues and what they’ve learned through the tests. Neither has yet reported an accident or serious safety issues. But they have had to train the vehicles to recognize buses and seagulls, and have said drivers have had to take control in construction areas and in other circumstances.