An early-morning crash on the eastbound lanes of Highway 401 at Winston Churchill Boulevard sent two people to hospital with serious injuries.
The eastbound lanes at Winston were expected to remain closed until 5 p.m., but one lane reopened to traffic shortly before 3 p.m. Thursday.
The accident happened around 12 a.m. when a tractor-trailer slammed into a truck protecting road workers, who were cleaning up a diesel spill from an earlier accident.
A worker on the road was seriously hurt in the crash and taken to Sunnybrook hospital with unknown injuries.
The driver of the transport truck was also rushed to hospital with serious, but non life-threatening injuries.
The OPP says the truck driver has been charged with careless driving.