WASHINGTON (Reuters) — A $1 trillion infrastructure bill under debate by the U.S. Senate includes a provision that directs U.S. regulators to mandate a passive technology to prevent intoxicated drivers from starting vehicles and avert more than 10,000 deaths annually.

For more than 15 years, automakers and others have studied potential technological fixes to address the roughly one-third of annual U.S. traffic deaths that involved impaired drivers.

The legislative push has won the backing of the advocacy group Mothers Against Drunk Driving, the auto insurance industry and some alcohol trade associations.

The Insurance Institute for Highway Safety (IIHS) said last year in a study that alcohol-detection systems that prevent impaired driving could save upward of 9,000 lives annually.

Drunk driving deaths cost the United States $44 billion in economic costs and $210 billion in comprehensive societal costs, according to a 2010 study. In addition, U.S. police departments arrest about 1 million people a year for alcohol-impaired driving, IIHS said.

Questions remain, however, whether the technology is accurate enough for widespread use and which one would be adopted.

In 2019, lawmakers told Reuters that automakers could use devices that would determine a driver’s blood-alcohol level by touching the steering wheel or engine start button or installing sensors that would passively monitor a driver’s breath or eye movements.

The bill would require the U.S. The Transportation Department will set a technology safety standard within three years and give automakers at least another two years to comply as long as new requirements are “reasonable, practicable, and appropriate.”

The bill said if regulators do not finalize new safety rules within 10 years, the department must report to Congress.

Some convicted drunk drivers are required to use breath-testing devices attached to an ignition interlock before starting their vehicles.

The Senate bill does not specify the technology but said it must “passively monitor the performance of a driver of a motor vehicle to accurately identify whether that driver may be impaired.”

Of the 36,096 traffic fatalities in 2019, an estimated 10,142 people were killed in alcohol-impaired driving crashes.

The National Highway Traffic Safety Administration and automakers have researched one system that samples a driver’s breathing, while another technology measures blood alcohol levels under the skin’s surface by shining an infrared light through the driver’s fingertip.

In 1974, Congress passed legislation reversing mandatory seat belt interlocks on automobiles. The government had mandated that vehicles sold after August 1973 require drivers to fasten safety belts before starting.