The drive in to work Thursday morning was a mess for many commuters on Highway 401 after a rig rolled over, spilling its load.

The tractor-trailer was carrying several containers filled with corrosive and flammable liquids that leaked all over the roadway after the early morning crash.

Ontario Provincial Police investigators believe the driver was going too fast on the Winston Churchill ramp to the highway, causing the vehicle to roll over and end up on its side.

They also contend the load was improperly secured.

Both the 401 eastbound's right lane and the southbound Winston Churchill ramp had to be closed for several hours during the morning rush as crews contained the leak.

It took longer than usual to clean up the mess because of the volatile nature of the spilled chemicals. Hazardous materials teams were sent to the scene to suck up the liquid into a second, secure container truck.

The affected routes were re-opened at about noon.