CORONA, Calif. (CNS) — The eastbound Riverside (91) Freeway in downtown Corona is slated to be shut down Friday evening and through the weekend — for the second time in less than a month — to enable crews to continue re-surfacing work, and motorists were advised to plan for alternate routes in advance, or be prepared for long delays in the construction zone.

The full eastbound closure is slated to start at 10 p.m. between Main Street and the 91/Interstate 15 interchange, with all five lanes out of service until 5 a.m. Monday, according to the Riverside County Transportation Commission.

The agency said that the second weekend closure is required for ongoing operations connected to the $12.6 million “91 Refresh Project,” which entails resurfacing lanes, modifying retaining walls and repairing concrete barriers on both sides of the 91.

“The closure is needed for the safety of motorists and crews while the paving work is under way,” according to an RCTC statement. “This work follows the full closure of eastbound 91 in this same area on Sept. 16-19. Crews will be replacing temporary asphalt placed that weekend with permanent concrete to give motorists a smoother ride.”

The project is expected to wrap up by December. It was not immediately known whether additional shutdowns might be required between now and then.

Although detours will be available via city streets through the mile-long closure zone, wait times are expected to be extensive, and eastbound motorists were encouraged to take other routes to their destinations.

The Pomona (60) Freeway to the north of the 91 will be open to all eastbound travel, as well as Interstate 10.

Officials said that even though the closure will end at I-15 in Corona, no lanes or transition ramps on the interstate will be impacted. The westbound 91 also will not be affected.

The Main Street on-ramp to the eastbound 91 will be closed as part of the weekend work.

The re-surfacing may conclude before the scheduled time on Monday, depending on conditions.

Motorists can get up-to-date information on the closure at www.rctc.org/91refresh.