Four people were sent to hospital early Saturday morning after a two-vehicle collision on Highway 401 near Milton.
Ontario Provincial Police said the crash occurred in the westbound lanes near the James Snow Parkway shortly before 5 a.m.
One vehicle rolled onto its roof, while the other ended up in a ditch.
Four people were taken to hospital with unknown injuries.
Police said one person was arrested at the scene for impaired driving.
The crash closed all westbound lanes of the highway for nearly two hours.
Meanwhile, a separate incident at about 7:30 a.m. closed four lanes of Highway 400 south of Bradford.
Police said a pickup truck was travelling south near Canal Road when it was rear-ended by a car. The impact sent the truck across all three lanes and into the ditch.
The car went airborne and crashed into a farmer's field. Police said the vehicle's two male occupants then fled on foot.
Officers called in the canine unit to search for the men, but the police dogs lost their trail in a marshy area.
Detectives located the two suspects in the afternoon. A 34-year-old Vaughan man has been charged with dangerous driving, driving while under suspension and failing to remain at the scene of an accident.
Police said the man was a mechanic and had decided to take the car that was being serviced for a joyride.
The driver of the truck suffered only minor injuries.
The accident closed two lanes in both directions of Highway 400.
