Another chaotic day on Highway 401 as a snowstorm triggered multi-vehicle collisions on the westbound lanes from Gananoque to Napanee.

OPP say at least 150 vehicles were involved in a series of crashes forcing the closure of westbound lanes.

A number of vehicles have slipped off the highway into the ditch.

Photos submitted to CTV News show a carnage of vehicles at Trenton with numerous vehicles involved including tractor trailers.

It will take emergency crews hours to clear that portion of the highway.

The highway at Napanee westbound recently reopened.

CTV's Claudia Cautillo will have a live report on CTV Ottawa News at 6.