Motorists can expect to encounter a detour for Highway 68 at the junction with Highway 169 in Mankato beginning this week as crews work to replace the bridge over the Union Pacific Railroad. Mn/DOT is replacing the 1936 bridge because it has reached the end of its useful lifespan. The preparation of the detour using Blue Earth County Road 50 and Highway 60 begins today (MON), with the detour then expected to be in place by mid-week and lasting until early October. Local Blue Earth County Roads 117 and 120 will be closed to commercial truck traffic due to railroad crossing safety. The Minneopa Trail will remain open with a short gravel bypass. Minnowa Construction of Harmony is the contractor on the $1.5-million project.