Drivers are advised to expect overnight traffic-pattern changes when travelling along Highway 1 westbound at Mount Lehman Road, starting as early as Monday, Aug. 31, 2026.

As work progresses to widen Highway 1 through the Fraser Valley, this detour is necessary to allow crews to safely install girders for the expanded Mount Lehman overpass. The structure is a key component of the Fraser Valley Highway 1 Corridor Improvement Program, which is dedicated to improving safety, reducing congestion and providing reliable travel for people.

During the detour, westbound traffic will temporarily shift to the Mount Lehman exit lane. The westbound on-ramp to Highway 1 from Fraser Highway will be closed, with drivers detoured via the Mount Lehman Road on-ramp. All other ramps will remain open.

The detour will be in place on multiple nights from Monday, Aug. 31 until Friday, Sept. 11, 2026, from 8:30 p.m. until 5:30 a.m. Sunday through Thursday, and 8:30 p.m. until 7 a.m. on Friday and Saturday.  

Drivers are reminded to use caution, obey signage and watch for roadside workers, and advised to allow for additional travel time through the area when diversions are underway.

Traffic and construction updates will be available on https://www.drivebc.ca/.