Carmakers say their increasingly sophisticated automated driving systems make driving safer and less stressful by leaving some of the hard work of knowing when a crash is about to happen--and avoiding it--to the machines. But new research suggests some of these systems might do the virtual opposite at the worst possible moment. A new paper from researchers at Ben-Gurion University of the Negev and the Japanese technology firm Fujitsu Limited demonstrates that when some camera-based automated driving systems are exposed to the flashing lights of emergency vehicles, they can no longer confidently identify objects on the road. The researchers call the phenomenon a "digital epileptic seizure"--epilepticar for short--where the systems, trained by artificial intelligence to distinguish between images of different road objects, fluctuate in effectiveness in time with the emergency lights' flashes. The effect is especially apparent in darkness, the researchers say.

U.S. safety investigators want to know why Tesla didn't file recall documents when it updated Autopilot software to better identify parked emergency vehicles, escalating a simmering clash between the automaker and regulators. In a letter to Tesla, the National Highway Traffic Safety Administration told the electric car maker Tuesday that it must recall vehicles if an over-the-internet update deals with a safety defect. "Any manufacturer issuing an over-the-air update that mitigates a defect that poses an unreasonable risk to motor vehicle safety is required to timely file an accompanying recall notice to NHTSA," the agency said in a letter to Eddie Gates, Tesla's director of field quality. The agency also ordered Tesla to provide information about its "Full Self-Driving" software that's being tested on public roads with some owners. The latest clash is another sign of escalating tensions between Tesla and the agency that regulates vehicle safety and partially automated driving systems.