If you're out on metro area roads this weekend, avoiding Interstate 35W in south Minneapolis might be a good idea.

The Minnesota Department of Transportation has shut down part of the freeway to take down the 38th Street bridge. That means a miles-long detour for drivers who use the highly traveled route connecting downtown Minneapolis with Crosstown Hwy. 62.

Until 5 a.m. Monday, the freeway's northbound lanes will be closed from the Crosstown to Interstate 94, and southbound lanes will be closed from I-94 to 46th Street. The bridge spanning the freeway closed at 6 a.m. Friday and will reopen sometime in August.

The official detour routes for I-35W drivers take them along Interstate 394, Hwy. 100 and Hwy. 62.

Motorists who use the 38th Street bridge to cross I-35W will be directed to use the 35th Street bridge (for those traveling west) or the 36th Street bridge (for those traveling east). Walkers can use the pedestrian bridge at 40th Street.

MnDOT spokesman David Aeikens asked drivers to avoid city and neighborhood streets to bypass the closure. "They are not designed to handle freeway traffic," he said.

Drivers looking to access I-35W at 36th Street will need an alternate route for much longer than the weekend. The ramp from 36th Street to southbound I-35W closed Friday and won't reopen until fall 2021.

That ramp closure and the 38th Street bridge project are part of the larger $239 million Downtown to Crosstown rebuild of I-35W, which began last year and will kick into high gear this summer. Over the next three years, MnDOT will reconfigure the flyover bridge from northbound I-35W to westbound I-94, build a new transit station in the center of I-35W at Lake Street and replace or refurbish 18 bridges along the 3-mile segment.

The project also adds new exits at Lake and 28th streets, a MnPass lane between 26th and 46th streets, and replaces the original pavement.

This weekend's work is just a preview of a more complicated and possibly exasperating summer driving season for Minneapolis motorists.

Around late June, northbound I-35W to the downtown exits — namely 5th Avenue and 11th Street — also will shut down for four months, forcing drivers to head over to 3rd Street or to Washington Avenue to access downtown.