By Karen Langley

Some Pennsylvanians caught driving drunk for the first time will be required to use ignition interlock devices under a bill Gov. Wolf signed into law Wednesday.

The law will leave only two U.S. states without some form of ignition interlock for first-time offenders, according to Mothers Against Drunk Driving, which advocated for the bill.

"Drunk driving is a deadly crime that puts Pennsylvania families at risk and this legislation will help prevent people from driving drunk and endangering themselves and putting other lives at risk," Wolf said. "We owe it to both motorists and pedestrians to keep them safe and hold people who break DUI laws accountable."

The new law requires drunk drivers with a first-time conviction and a blood alcohol concentration of .10 or greater to use ignition interlocks for at least one year. Supporters of requiring ignition interlocks say they protect people on the roads while also allowing offenders to keep a job and meet other responsibilities.

Until now, Pennsylvania has required ignition interlock only for repeat drunk drivers.

The interlock requirement takes effect in 15 months.

Ignition interlock devices require a driver to blow into a tube that measures the presence of alcohol. If an unacceptable blood alcohol level is detected, the vehicle will not start.

A report from Mothers Against Drunk Driving found that between October 2003 and December 2015 more than 78,000 attempts to drive drunk in Pennsylvania were stopped by ignition interlock.

Many Pennsylvania drivers caught for the first time operating a vehicle under the influence would not be affected by the new law because they go through a process, called accelerated rehabilitative disposition, that can leave them without a conviction, said Stephen Erni, executive director of the PA DUI Association.

Erni estimated that the new law will lead to 13,000 additional Pennsylvania drivers with an ignition interlock device, up from about 6,000 now.

After years of lobbying by advocates, the legislation this year was approved easily, passing the House 193-2 and the Senate 50-0.

Statistics from the Pennsylvania Department of Transportation show 10,288 collisions statewide involving drinking drivers in 2015.

(c)2016 The Philadelphia Inquirer