Starting Saturday, the Missouri Department of Transportation will make lane closures on the Interstate 435 bridge over the Missouri River to prepare for a two-year rehabilitation project on the aging bridge.

The bridge, which straddles Jackson and Clay counties, was built in 1972 and has about 81,500 crossing each day, including many tractor trailers given its proximity to industrial areas. The road closures have the potential to cause significant backups or slowdowns.

The following lane reductions will take place for traffic realignment work:

• Crews will reduce southbound I-435 down to one lane between Parvin Road (north of the river) and Front Street (south of the river) from 7 a.m. Saturday until 5 a.m. Monday.

• Crews will also reduce southbound I-435 down to one lane between Parvin and Front from 9 a.m.-3 p.m. Monday and Tuesday.

• Crews will close the ramps from eastbound and westbound Missouri 210 to southbound I-435 from 7 a.m-7 p.m. Saturday. Missouri 210 traffic wishing to travel south on I-435 should travel north on I-435 and turn around at the Parvin Road exit.

• Crews will reduce northbound I-435 down to one lane between Front and Parvin from 9 a.m.-3 p.m. daily, beginning Tuesday, March 17, and continuing through Friday, March 20.

The repair project includes bridge deck replacement, reinforcing the structural steel girders and substructure repairs, as well as extending the acceleration lane from M-210 to I-435 south. In addition, crews will also do bridge scour repair work. Bridge scour happens when sediment from around the bridge abutments or piers is scooped out and removed over time by swift-moving water, and a large enough scour hole can compromise the bridge's integrity.