Three separate accidents along Highway 401 this morning have caused traffic headaches for commuters in the Greater Toronto Area.

The eastbound express lanes were blocked just before the Don Valley Parkway because of a tractor-trailer that jackknifed and collided with two other transport trucks. That jammed the express lanes as far back as Keele Street, and was leading to heavy traffic in the collector lanes as well as slow-downs in the westbound lanes.

Emergency personnel were at the scene, and Ontario Provincial Police said they had cleared one of the blocked lanes by 9:30 a.m. and expected to open the rest by 10 a.m.

West of Toronto, one eastbound lane and two westbound lanes were closed near Guelph Line because a tractor-trailer went through the guard rail and spilled fuel. The OPP said the closures could last several hours and recommended motorists use an alternate route.

And east of the city, in Whitby, a Go bus and a tractor-trailer collided on the 401 westbound, but the vehicles were on the paved shoulder and traffic was clear.