The 38th Street bridge over Interstate 35W in south Minneapolis is coming down this weekend, and the Minnesota Department of Transportation will shut down the freeway to get the work done.

That means a miles-long detour for drivers who use the highly traveled route connecting downtown Minneapolis with Crosstown Hwy. 62.

From 10 p.m. Friday until 5 a.m. Monday, the northbound lanes will be closed from the Crosstown to Interstate 94, and southbound lanes will be closed from Interstate 94 to 46th Street. The bridge spanning the freeway will close at 6 a.m. Friday and reopen sometime in August.

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

For motorists who use the 38th Street bridge to cross I-35W, those heading west will be directed to use the 35th Street bridge while those heading east will be sent to 36th Street. Those traveling on foot can use the pedestrian bridge at 40th Street.

"Weekend closures are a challenge for people, so we ask them to plan ahead, select an alternate route and provide additional time to reach their destination," MnDOT spokesman David Aeikens said.

And he pleaded with drivers not to opt for city and neighborhood streets to bypass the closure. "They are not designed to handle freeway traffic," he said.

The bridge and freeway closures come on a weekend when the event calendar is somewhat light, although Target Center hosts several performances of "Disney on Ice" while the state high school wrestling tournament and a Sunday Wild game take place at the Xcel Energy Center in St. Paul.

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 will close at 6 a.m. Friday and won't reopen for three years until the fall of 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 includes adding new exits at Lake and 28th streets, adding a MnPass lane between 26th and 46th streets, and replacing the original pavement, which was put down in 1965 and patched up all these years.

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.

That closure "will probably be worse and more challenging" than last summer's I-94 tie-ups for the Lowry Hill Tunnel remake, Aeikens said.

One bit of good news: Construction on the new Franklin Avenue bridge is on schedule and the bridge is expected to open in late May or early June.

Tim Harlow • 612-673-7768