Route D was closed Aug. 1 to begin replacement of a bridge over a branch of Tuque Creek east of Marthasville, between Rebecca Lane and Wolf Creek Road.
The 72-year-old bridge will take about 37 working days to replace, according to Missouri Department of Transportation officials.
The new bridge will be four feet wider and will open to traffic in early September.
Alternate routes include traveling over Highway 94 and Route TT.
For more information, people may call MoDOT at 888-275-6636 or visit www.modot.mo.gov/northeast.