Provincial police closed the westbound lanes of Highway 402 at Kerwood Road Tuesday afternoon after a commercial vehicle rolled onto its side.
The single-vehicle collision, between Watford and Strathroy, was reported at around 3 p.m. Provincial police said the collision occurred between Sexton Road and Donnelly Road.
No other details were immediately available.
OPP from Lambton and Middlesex, and volunteer firefighters responded to the scene.
Motorists were asked not to drive around road closure barriers and to follow signage for returning to the highway.