Transportation department spokesman Tim Greeley said the delays were caused when a support pillar on a bridge under construction at College Farm Road shifted Tuesday afternoon.
The situation forced officials to close the northbound lanes and detour traffic onto an adjacent access road.
Officials orderede a full structural evaluation of the bridge, which should be completed on Wednesday.
The northbound lanes were expected to be closed until Thursday at 8:00 p.m. because of the repairs.
Motorists who normally use Route 1 northbound are urged to seek an alternate route.
DOT said the southbound side is not impacted by the problem.
