Feds query Tesla over Autopilot after crash

DETROIT — Federal investigators looking into electric carmaker Tesla Motors’ Autopilot system after a fatal crash in Florida are zeroing in on the limitations of the system and how it reacts when obstacles cross its path.

The National Highway Traffic Safety Administration on Tuesday posted a nine-page letter seeking information from Tesla about Autopilot and why it failed to detect a tractor-trailer that crossed in front of a Model S sedan May 7 in Williston, Fla.

Much of the letter seeks information on how the system works at intersections with crossing traffic, but it also asks Tesla to describe how the system detects “compromised or degraded” signals from cameras and other sensors and how such problems are communicated to drivers.

The safety agency also asked Tesla for its reconstruction of the crash, and for details of all known crashes, consumer complaints and lawsuits filed or settled because the Autopilot system didn’t brake as expected.

Tesla’s Autopilot system uses cameras, radar and computers to detect objects and automatically brake if the car is about to hit something.

Some safety advocates have questioned whether the company — which says the system is still in “beta” phase, a computer industry term for software testing by customers — and NHTSA allowed the public access to the system too soon.