Traffic was backed up for kilometres on the 401 Friday morning following a tractor trailer rollover shortly after midnight.
The transport truck was carrying non-hazardous "dry freight" when it rolled over in the westbound lanes of the highway at about 12:50 a.m., blocking all lanes, said Const. Julia McCuaig of the OPP.
No other vehicles were involved in the accident just west of Lakeridge Road.
"The tractor trailer went over to the right side, not leaving the highway, then went over to the left striking the centre median. So there was extensive guardrail damage and the (Ministry of Transportation) will be doing some repairs this morning," McCuaig told CTV.ca.
In the hours after the accident, some traffic was able to pass on the right shoulder, but a major jam started to develop as rush hour approached, she said.
At its peak, the jam reached all the way to Whitby, snarling the busy morning commute as well as alternative routes such as Highway 2.
The contents of the rig were transferred to another truck, and the rig was righted at about 6:30 a.m.
By 7:20 a.m. all lanes were once again open. However, it took another hour before the backup began to subside and traffic began returning to normal, McCuaig said.
The driver of the truck was taken to hospital in Ajax for treatment of minor injuries.
