The St. Patrick Street underpass will be closed to all traffic from 8 a.m. to 2:30 p.m. Monday and again in the first week of December for railroad overpass repairs, state highway officials said Tuesday.

Workers will be doing routine maintenance on the Union Pacific Railroad bridge over St. Patrick, also known as La. 945. The St. Patrick underpass is a key route into Donaldsonville southwest of La. 3089 and the Union Pacific line.

The closures next month at St. Patrick will last from Dec. 1-4 for the same daytime hours, officials with the state Department of Transportation and Development said.

DOTD advised drivers to use La. 3089, La. 308 or La. 945 off La. 308 as detour routes.