Tractor underwater Floodwaters have covered roads up and down the Mississippi River, with highways north of St. Louis to the Iowa line at Alexandria especially affected. Mississippi floodwaters have also closed a number of highways south of St. Louis.

Now, flash flooding has wreaked havoc in north-central Missouri. Up to nine inches of rain fell in portions of north-central Missouri, closing many of the so-called "lettered" roads and even making passage on Highways 36 and 24 uncertain. The Missouri Department of Transportation has an informational map on its Web page that displays the latest road closings due to high water. Motorists can also call 1-800-ASK-MODOT to get the latest information on road conditions.

Jeff Briggs, a spokesman for MoDOT, cautions motorists against trying to drive through high water. He says motorists can never be sure how much water is over the road and whether it can be safely driven through.

Download/listen Brent Martin interviews Jeff Briggs of MoDOT on road conditions (7:20 MP3)