Intelligent braking systems can predict a collision, while blind spot sensors warn drivers not to change lanes.
But what if standard car safety systems could detect if a driver had consumed too much alcohol?
As soon as 2026, automakers would be required to equip cars with technology geared toward preventing drunken or impaired driving under a key provision of the trillion-dollar infrastructure package that awaits President Biden’s signature.
The type of technology that would be used is far from settled, with Congress stopping short of endorsing ignition lock devices like those that are often required by the courts for drunken-driving offenders and involve a breath test.
But organizations like Mothers Against Drunk Driving say that the safety mandate would save thousands of lives. The group pointed out that more than 9,000 people are killed each year in the United States in drunken-driving accidents, citing a 2020 study by the Insurance Institute for Highway Safety.
Alex Otte, the president of MADD, said in a recent statement that the measure would “virtually eliminate the No. 1 killer on America’s roads.”
“We need technology to stop the nightmare on our roads,” Ms. Otte said. “Existing technologies and those in development will stop the hazardous driving behavior of people who refuse to make the right choice themselves.”
Under the mandate, the safety equipment must “passively monitor the performance of a driver of a motor vehicle to accurately identify whether that driver may be impaired” and “prevent or limit motor vehicle operation if an impairment is detected.”
It was not immediately clear what lawmakers considered to be passive monitoring.
Congress gave the National Highway Traffic Safety Administration three years to issue a final rule for the safety devices, which the bill said would give automakers adequate time to comply with the measure.
The agency did not immediately comment on Wednesday.
The mandate’s proponents noted that 68 percent of fatal drunken-driving accidents in 2019 involved drivers with a blood-alcohol concentration of 0.15 percent or higher. The legal limit is 0.08 percent.
John Bozzella, the president and chief executive of the Alliance for Automotive Innovation, said in a statement this week that the industry group appreciated that lawmakers gave safety regulators flexibility to review different technology options.
“The auto industry has long been committed to supporting public and private efforts to address this tragic threat to road safety, which contributes to more than 10,000 lives lost each year,” Mr. Bozzella said. “A number of provisions in this legislation take on this important challenge, from support for enforcement to the advancement of potentially life-saving technologies.”
In a letter to the National Highway Traffic Safety Administration in January, the alliance’s vice president for safety policy, Scott Schmidt, said that it was critical that drunken-driving deterrent systems use precise data about a driver’s blood-alcohol concentration.
Alternative driving monitoring systems, including those relying on cameras, could produce false positives, he said.
Mr. Schmidt recalled that in the 1970s federal regulators adopted a rule that cars couldn’t start unless drivers fastened their seatbelts, but that it was rescinded because of its unpopularity.
“Given the nature of alcohol impairment, driver warnings and mild interventions will likely be ineffective,” Mr. Schmidt said. “As a result, intrusive interventions would be required. If such interventions are needed, system accuracy must be very high in order to meet consumer acceptance expectations and avoid consumer backlash.”