OTTAWA -- The westbound lanes on Highway 401 have reopened near Cornwall after an early morning crash involving several tractor-tractor trailers closed the lanes completely.

Police say four separate crashes happened shortly before 6 a.m. when several trucks left the roadway and entered the median on the highway east of Cornwall, between the Summerstown and McConnell Avenue exits.

Two passenger vehicles also left the roadway in the same area.

Police say no one was injured.

Speaking to CTV News at the scene OPP Const. Tylor Copeland said four tractor trailers were involved.

"They were all separate incidents and there were no injuries reported in any of the collisions," Copeland said.

One of the factors police are investigating is road conditions.

"There was some snow overnight and it caused some slippery conditions," Copeland said. "Drivers should be aware of changing road conditions and drive accordingly."

OPP tweeted that lanes had fully reopened just before 3:30 p.m.