Keith Laing

Detroit News Washington Bureau

Washington — U.S. regulators are cautioning General Motors Co. about its planned semi-autonomous Super Cruise system that will slowly bring a car to a halt if the system senses the driver is inattentive.

The National Highway Traffic Safety Administration said GM’s proposal to stop cars with unresponsive drivers and then automatically activate hazard flashers is compliant with federal automotive standards. But the agency wants to make sure activating the emergency flashers isn’t misinterpreted by other drivers and doesn’t present “an unreasonable risk to safety.”

GM spokesman Kevin Kelly on Tuesday confirmed the company’s plans for the system, saying the Detroit-based automaker thinks “it’s the safest thing to do” in the event of a human driver not being able to retake control of the vehicle.

“If we’ve tried repeatedly to re-engage the driver and we think there might be an issue ... we will slow down the vehicle (and turn on hazard flashers),” he said.

The Super Cruise feature controls steering, braking and acceleration in certain freeway situations. It will allow drivers to take their hands off the steering wheel and feet off the pedals while driving. The system monitors facial cues; if it senses the driver is sleeping or not paying attention, it sends visual warnings, including a light bar on the steering wheel, and then audio warnings.

The system is expected to debut next year on the flagship Cadillac CT6 sedan.

A letter from NHTSA to GM earlier this month related the automaker’s description of Super Cruise in this way: “If the driver is unable or unwilling to take control of the wheel (if, for example, the driver is incapacitated or unresponsive), Super Cruise may determine that the safest thing to do is to bring the vehicle slowly to a stop in or near the roadway, and the vehicle’s brakes will hold the vehicle until overridden by the driver.”

GM requested an interpretation about the warning hazard flashers from NHTSA in March after delaying its planned introduction of the Super Cruise feature on the Cadillac CT6. GM originally had said the technology would be available late this year. That has been pushed back to next year.

NHTSA Chief Counsel Paul Hemmersbaugh said GM’s plan to use hazard lights to indicate problems after the car is stopped “is the prototypical situation in which the hazard lights are intended to be used and it is one of the situations that other motorists have come to expect when they see the hazard signal.”

He added: “Any other automatic activation of hazard warning lights would need to be evaluated on a case-by-case basis. NHTSA may also consider amending the relevant provisions of (federal motor vehicle standards) at some point in the future in order to clarify situations when hazard lights may activate automatically.”

klaing@detroitnews.com

Detroit News staff writer Michael Wayland contributed.