Drivers heading northbound on Interstate 15 near Helena are dealing with a right lane closure that will remain in place through July 3. The construction zone runs from milepost 146.0 to 148.0 — a roughly two-mile stretch — with speed limits dropping to between 35 and 55 mph and a 16-foot width restriction in effect.

The work involves shoulder widening and installation of new barrier rail, the kind of infrastructure upgrade that extends the life of a heavily traveled corridor. The closure began at 6 a.m. Monday, June 8, and is scheduled to lift at 7 p.m. on July 3 — meaning it will be in place through the Fourth of July travel weekend.

Drivers with wide loads or those towing trailers should plan accordingly given the 16-foot width limit. Montana Department of Transportation advises motorists to slow down and stay alert in construction zones.