An overnight 15-minute pace change will reduce the speed for traffic on the Pennsylvania Turnpike starting at midnight between the westbound Allegheny Valley and Butler Valley interchanges.

No major delays are expected, but drivers should be prepared for slow-moving traffic and possible stoppages, according to a news release.

Renee Vid Colborn, manager of media and public relations for the Turnpike, said the change will occur between Exits 48 and 39 to allow crews to switch to a new traffic pattern.

She said the change is being made to allow the safe completion of the traffic switch between mileposts 40 and 44, and motorists should expect “no significant delays.”

“We do it at midnight because that’s when there is the least amount of traffic,” she said.

During the pace, turnpike maintenance and state police vehicles will restrict traffic to 20 to 25 mph, according to the news release.

The new traffic pattern will allow work to begin on the second phase of the milepost 40 to 48 total reconstruction project.

The second phase, between mileposts 40 and 44, is scheduled for completion in fall of 2019.

For more information on this project, visit www.mp40-48construction.com.