A law requiring some people in Pennsylvania convicted of driving under the influence to install ignition interlocks in their vehicles went into effect in August.
But could laws requiring interlocks for all impaired-driving offenders save more lives?
A study released in March by the Insurance Institute for Highway Safety found that installing interlocks in vehicles of all DUI offenders reduces the number of impaired drivers in fatal crashes by 16 percent. If all states mandated laws requiring interlocks, according to the study, more than 500 lives could be saved each year.
“We looked at the number of impaired passenger vehicle drivers involved in fatal crashes over time and compared them with the number of drivers in fatal crashes that didn’t involve impairment,” said Eric Teoh, IIHS senior statistician and the lead author of a report released alongside the study. “We found that state laws mandating interlocks for all DUI offenders reduced the number of drivers in fatal crashes with BACs of 0.08 percent or higher by 16 percent compared with no interlock law.”
Ignition interlock devices require drivers to blow into a tube that measures the presence of alcohol. If the devices detect an unacceptable amount of alcohol, the vehicles will not start.
A total of 28 states as well as Washington, D.C. and four California counties mandate some sort of interlock requirement for all offenders, but not Pennsylvania.
Supporters of the Pennsylvania law said it would protect other drivers while also ensuring that people with first-time DUI convictions can drive to keep a job and meet other responsibilities.
Pennsylvania requires people with a first-time DUI conviction and a blood-alcohol content of at least 0.10 to use the devices for at least a year. Drivers who refuse to undergo a blood-alcohol test would have their licenses suspended for 12 to 18 months but could be eligible for an ignition interlock device after serving six months of that suspension.
The law does not affect all first-time offenders, though. Some people could chose to enter the accelerated rehabilitative disposition program, which allows offenders to have their charges withdrawn if completed successfully.
The study compared alcohol-impaired passenger vehicle drivers involved in fatal crashes between 2001 and 2014 in the United States across state and time. State and time differences unrelated to interlock laws were controlled by using a statistics method known as a Poisson model. The exposure measure was the number of passenger vehicle drivers in fatal crashes that did not involve impaired drivers.
According to the Pennsylvania Department of Transportation, 297 people died in 10,256 alcohol-related crashes in the state in 2016, the latest year that statistics were available.
“Whether interlocks keep those convicted of DUI from re-offending or deter people generally from driving while impaired, the overarching goal is to reduce alcohol-impaired driving and the deaths and injuries that result,” the IIHS status report said. “The national study shows they have succeeded.”
Andrew Goldstein: agoldstein@post-gazette.com or 412-263-1352.
First Published: April 2, 2018, 4:00 a.m.