South Carolina will raise speed limits on some of the state's interstate highways from 65 mph to 70 mph.
Speeds through construction areas on interstates 26 and 85, and congested areas will not change.
"Most places that it's 65 will probably go to 70," said Rick Werts, traffic engineering director for the state Transportation Department. "But we've identified some sections that are fairly congested or were not built to 70 miles per hour design speed."
States got the power to set their speed limits in 1995, but the effort in South Carolina has been a hard-fought battle. Opponents have stalled the proposal in previous years by tacking on seat-belt enforcement measures, warning that increased speed means more accidents.
In urban areas, the speed limit will be increased to 65 mph or 60 mph, depending on traffic conditions. In some heavily congested areas the limit will stay at 55 mph.