Road projects start Monday in Marion and Mt. Vernon.

The Illinois Department of Transportation says drivers on Illinois Route 13 in Marion will begin transitioning onto the eastbound structure over the railroad tracks and Marathon Drive at 7 p.m. Thursday. Most work will be completed between 7 p.m. and 7 a.m., and IDOT says delays near the area should be expected until Thursday morning.

IDOT also says there will be lane reductions on both highways around the I-57 and I-64 interchange for patching work and asphalt pavement. Detours are marked.