Essentially in-car breathalyzers, the "ignition interlocks" led to a 15 percent decline in alcohol-related deaths in 18 states that required them for anyone convicted of drunken driving, the researchers found.
Article continues below
The estimated 915 lives saved from 2007 to 2013 is comparable to the lives saved by mandatory airbag laws and the 21-year-old drinking age, the study authors noted.
"The number of times that I have had to talk to a family and tell them that they lost their son or brother or daughter or sister to something so preventable as a drunk driving crash, it's hard to count even in my short time of practice - that's my motivation," said study author Dr. Elinore Kaufman, a student in the health policy program at the University of Pennsylvania in Philadelphia.
"Other states have proven [a mandatory interlock law] is feasible, and we're contributing proof that it is effective," said Kaufman. "There should be no remaining barrier for the remaining half of states to adopt it."
J.T. Griffin, chief government affairs officer for Mothers Against Drunk Driving (MADD), welcomed the findings. He said the study validates what MADD has been saying since 2006.
"We've been working to pass these laws, and we think you can get better than a 15 percent reduction" in alcohol-related crash deaths, he said. "But a 15 percent reduction is really good. If we could do it nationwide, it could save 1,500 lives a year. That's a lot of people."
Thirty percent of deadly car crashes in the United States are alcohol-related, claiming an estimated 11,000 lives every year, the study authors said.
To start a car equipped with an ignition interlock, you blow into the breathalyzer. If your blood alcohol count is over a set limit - usually 0.02 - the engine won't start. Someone with a blood alcohol level of 0.02 is considered mildly impaired. Many people reach that level after just one drink.
The devices have previously been shown to curb repeat DWI offenses by between 50 percent and 90 percent, the researchers said. The new study is believed to be the first to examine whether ignition locks also reduce alcohol-related injuries and deaths. ■