New Delhi, Oct. 12 -- WASHINGTON - Federal regulators have cleared driverless trucks to use flashing beacons mounted on the cab in place of the warning triangles that a human driver sets out behind a stopped rig. The Federal Motor Carrier Safety Administration granted a limited five-year exemption that took effect October 7, according to its decision notice, removing a rule that had no practical answer when nobody is in the truck.

The exemption covers Aurora Operations and any other carrier running trucks with a Level 4 automated driving system, provided the carrier notifies FMCSA in writing before it uses it. It waives the federal requirements on where warning devices are placed around a stopped vehicle, on steady-burning lamps, and on ...