With safety in mind, the speed limit for the U.S. 278 construction zone will drop soon to 45 mph, according to a news release.

The 10-mph decrease will span a five-mile stretch between the S.C. 170 overpass bridge and Simmonsville Road in Bluffton. That segment is being widened. Speed-limit signs are being replaced, and the change should be in effect within a week, according to Leslie West, project manager for contractor APAC-Southeast Inc.

The lower limit will remain until the project's completion, scheduled for November 2013, West said.

There will also be a lane shift from 9 p.m. to 6 a.m. Wednesday, from the S.C. 170 overpass bridge to the bridge over the Okatie River, West said. The eastbound lanes will move south by six feet, and the westbound lanes will move six feet north. All lanes will remain open, he said, barring the required nightly lane closures already in effect.

Drivers are asked to use caution when traveling through the construction zone.