Traffic on U.S. Highway 26 over Mount Hood will be restricted starting next week, with the beginning of a multiyear Oregon Department of Transportation project to improve safety on the Portland side of Government Camp.

Starting Monday, an excavation company working on the project will reduce traffic to one lane in each direction on a 2½-mile stretch of highway from east of Kiwanis Camp Road to east of Mirror Lake.

The partial closure is expected to remain in place through the end of October. Construction will be put on hold between November and April and is expected to be completed in 2016.

ODOT spokeswoman Kimberly Dinwiddie said the roughly $22 million project will address two long-running safety issues — rocks falling on the roadway from cliffs up to 100 feet tall, and crashes involving drivers crossing the centerline.

Between 2002 and 2011, ODOT documented 109 crashes on this stretch, in which 88 people were injured and four people were killed.

Dinwiddie said that starting next week, crews will set up a temporary barrier allowing them to inspect the cliffs. Estimates suggest there may be as much as 1 million cubic yards of rock that needs to be removed, she said, and the contractor will begin excavating the rock and inspecting the area to determine how to best tackle the effort.

Much of the rock will be removed through blasting, Dinwiddie said, but it is not yet clear how much will be needed. During blasting, which will be scheduled 5:30 to 7:30 p.m. for up to three nights a week, the highway will be closed to all traffic for up to an hour.

Dates for the blasting have not yet been set, but will be announced in advance on ODOT’s TripCheck.com website.

Drivers should anticipate traffic stops of up to 20 minutes when blasting is not taking place.

Dinwiddie said this summer and next summer will be largely dedicated to rock removal.

By summer 2016, crews will be able to shift to work that will be less disruptive to drivers, she said, putting up new signs, repaving the road and installing a concrete center line barrier to eliminate head-on collisions.

— Reporter: 541-383-0387, shammers@bendbulletin.com