ST. LOUIS — Attention Saint Charles drivers: plan for slowdowns on Interstate 70 this weekend. Modot crews will close all lanes of 70 at the Zumbehl Road exit at ten o’clock tonight, weather permitting. That’s so they can demolish the old bridge going over the highway. Traffic in both directions will be routed up and over the ramps. That section of 70 will reopen by Monday morning. Drivers are encouraged to take Highway 370 or Highway 364 in the meantime. Zumbehl will also be closed between West Clay and Veterans Memorial Parkway. Drivers should use hawk’s nests or cave springs.