US car safety regulators said on Tuesday they have begun the process that will eventually force motoring manufacturers to adopt new technology to prevent intoxicated drivers from starting vehicles.

In 2021, the US congress directed the National Highway Traffic Safety Administration (NHTSA) to mandate a passive technology to try to avert more than 10 000 road deaths annually. The law requires a new technology safety standard by November 2024 if the technology is ready.

There are a number of potential technologies under development that would prevent impaired people from starting a vehicle, including breath- or touch-based sensors to detect alcohol. Another potential option is using cameras to monitor eye movements to try to determine if drivers are intoxicated.

Still, NHTSA must be assured the technology works before it can require it, and then give car makers at least three years to implement it once it finalises rules.

“We are trying to see can we get it done, does the technology exist in a way that is going to work every time?” acting NHTSA administrator Ann Carlson said, adding that public acceptance of the technology would depend on its accuracy.

Carlson said there were close to a billion separate daily driving journeys in the US.

“If it’s 99.9% accurate, you could have a million false positives,” Carlson said. “Those false positives could be somebody trying to get to the hospital for an emergency.”

The NHTSA on Tuesday published an “advance notice of proposed rulemaking” to begin the process of gathering information on how such technology could be developed and required.

‘Mountain to climb’

Its regulatory notice details the research and technological advancements needed to finalise regulations and options for potential rules, citing “blood alcohol content detection, impairment-detection (driver monitoring), or a combination.”

Mothers Against Drunk Driving president Tess Rowland said the group was “very pleased” with NHTSA’s launch. “We understand we still have a mountain to climb,” she said. “Victims and survivors are not going to let this die.”