The Missouri DOT is urging truckers to use I-270 and Mo. 370 as an alternate route to the Interstate 70 bridge over the Missouri River between St. Louis and St. Charles.

DOT is replacing the westbound I-70 Blanchette Bridge over the Missouri River at mile marker 230. This weekend, the westbound bridge will shut down for demolition and rebuilding of most of its structure.

During construction, all traffic will share the eastbound bridge, with three, narrow lanes - 10 to 11 feet wide - running in each direction. A 45-mph speed limit is set for the work zone.

At noon, Friday, Nov. 2, two eastbound lanes of I-70 will close beginning at mile marker 228. Three lanes will remain open. Transfer of the westbound lanes onto the other bridge will begin at 10 p.m. Friday night. The lane changes begin at mile marker 231.

The westbound bridge will remain closed until Fall 2013.

Commercial motor vehicle drivers are urged to use I-270 and Mo. 370 as an alternate. This adds five miles to the route, but with expected I-70 congestion and a 45 mph work zone speed limit, using Mo. Route 370 is expected to be a quicker option.

- Eastbound: I-70 to Mo. 370 East to I-270 South to I-70 East
- Westbound: I-70 to I-270 North to Mo. 370 West to I-70 West

HazMat drivers and carriers are especially urged to use Mo. 370 and avoid the construction area. Small fender-benders in the work zone are expected to result hour-long delays. A crash involving hazmat near a major river could snarl progress for hours.

The westbound I-70 bridge over the Missouri River was built in the late 1950s. It is in serious need of major repairs. Without major repairs, the bridge will continue to fall into disrepair and emergency repairs will be required at more frequent internals with longer traffic closures.

To learn more, visit www.modot.org/blanchettebridge.