Legislation passed in October by the General Assembly and signed by Gov. Tom Wolf established the state's first felony for DUI.
It applies when someone has been charged with a third offense in a decade with at least twice the legal limit for alcohol, or any fourth-time offender. Pennsylvania law sets the legal limit for driving at 0.08 percent.
Previously, all DUI offenses in Pennsylvania had been treated as misdemeanors, which carry lighter penalties and fewer other consequences.
"What we think will happen is that people are going to have another reason not to drive impaired against after the first time," Chris Demko of Pennsylvania Parents Against Impaired Driving told Pennlive.com .
Demko's 18-year-old daughter was killed by a repeat DUI offender four years ago.
- Boy, 17, shot in back by 12-year-old brother at Pine Township home
- Government shutdown: President Trump says it will last 'until we have a wall'
- Better to give: Man uses own food stamps to feed others on Christmas
- VIDEO: Community, police department rally around officer after cancer returns
- DOWNLOAD the Channel 11 News app for breaking news alerts
The new law also mandates longer jail time for those who unintentionally cause someone's death because of a repeat DUI violation.
"At a bare minimum, it's going to take some of the worst offenders off the road for a longer period of time when they get caught, so they can't go out and kill anybody," Demko said.
The stiffer penalties for repeatedly driving drunk in Pennsylvania took effect Sunday. They include increased fines and penalties for driving under the influence on a license suspended because of a DUI conviction.
Pennsylvania has about 10,000 alcohol-related crashes and 300 fatalities annually.
Pennlive.com says there are about 250,000 repeat DUI offenders in Pennsylvania and about 140,000 persons whose licenses are currently suspended because of a DUI.
Copyright 2019 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.