First responders were called to a crash on Highway 402 in Sarnia late Friday morning.
Lambton OPP closed the westbound lanes of the highway, just west of Modeland Road, before the noon hour.
Motorists heading towards the Blue Water Bridge were being advised to take an alternate route.
There's no word on injuries or a cause of the crash.
The highway reopened to traffic just before 2:30 p.m.