Top U.S. vehicle safety regulator stands by self-driving cars

National Highway Traffic Safety Administration chief Mark Rosekind said at a conference Wednesday the agency is bullish on the potential of autonomous driving technology to reduce the 94 percent of car crashes attributed to human error.

"No one incident will derail the Department of Transportation and NHTSA from its mission to improve safety on the roads by pursuing new lifesaving technologies," Rosekind said.

The comments follow the May 7 fatal crash in Florida of a Tesla Motors Inc Model S car while it was using the vehicle's "Autopilot" software that allows drivers to take their hands off the steering wheel at times.

NHTSA has said it is working on guidelines for safely deploying automated vehicles and how they should behave in a variety of conditions. The agency had planned to release its guidance by July 14. Transportation Secretary Anthony Foxx said Tuesday it may not be released until "late summer."

NHTSA has also opened a formal investigation into the Model S fatal crash. Rosekind and Foxx in Washington both declined Wednesday to comment on the Tesla investigation.

Autonomous vehicles must be "much safer" than human drivers before they are deployed on U.S. roads, Rosekind said. He did not quantify how much safer.

"If we wait for perfect, we’ll be waiting for a very, very long time," he said. "How many lives might we be losing while we wait?"

Rosekind said self-driving cars will be able to improve even as they make mistakes. Data from an accident involving a self-driving car "can be taken, analyzed, and then the lessons can be shared" with manufacturers of all automated vehicles, Rosekind said.

Human drivers "must learn on the road and make the same mistakes as thousands before them," he said.

(Reporting by David Shepardson; Editing by Andrew Hay)