According to OPP, a transport crashed in the westbound lanes of Highway 401 Friday afternoon west of County Road 4 and the OnRoute, near Napanee.
Several other minor collisions, prompted by another jackknifed transport, have caused the closure of the westbound lanes of the highway.
In total, there were three multi-vehicle collisions in the westbound lanes and another multi-vehicle collision in the eastbound lanes.
Four people were taken by ambulance with minor injuries from one multi-vehicle collision.
Police say other vehicles were damaged, but those inside escaped without injury.
Police have created a detour route off the highway to County Road 4, then to County Road 2, west to Palace Road, then north back to Highway 401.
Expect traffic delays on the highway.