The Virginia Department of Transportation is putting in nighttime detours on Interstate 81 South in Montgomery County starting Sunday.

The detour will be put in place at Exit 132 (Dixie Caverns), onto Route 460, and back onto I-81 at Exit 118 (Christiansburg). The detour runs from Sunday to Thursday, from 10 p.m. to 6 a.m. each night.

The detour is part of a VDOT truck climbing project.

The entire project will be finished in November.