Come Monday, commuters who use Hwy. 100 through St. Louis Park will have fewer lanes to use, but first comes a weekend closure to take down a railroad bridge pier and reconfigure the highway.

From 10 p.m. Friday until 5 a.m. Monday, both directions of Hwy. 100 will be closed between I-394 and the Crosstown . Ramps and some travel lanes along that stretch will begin closing at 9 p.m. Friday, the Minnesota Department of Transportation said.

During the closure, motorists will be detoured along I-394 and Hwys. 169 and 62.

The 132,000 commuters who use the highway each day might want to continue that detour once Hwy. 100 reopens on Monday. Traffic will be reduced from three lanes to two lanes in each direction between Barry Street and W. 36th Street and big delays are expected.

Over the next two years, MnDOT is spending $60 million to upgrade the substandard section of highway and rebuild bridges at Hwy. 7 and Minnetonka Blvd. The project also includes adding an auxiliary lane and noise walls.

Earlier this week, MnDOT shut down the Minnetonka Blvd. bridge over Hwy. 100. Motorists are being detoured via Lake Street, Wooddale Avenue and Hwy 7.

Additionally the following ramps are closed: Minnetonka Boulevard to southbound Hwy 100, Minnetonka Boulevard to northbound Hwy 100 and northbound Hwy 100 to Minnetonka Boulevard.