A crash set ablaze a semi-trailer on Winnipeg's south Perimeter Highway on Thursday.

A concrete pumping truck and semi were westbound on the Perimeter near St. Anne's Road just after 7 a.m. when a pickup truck attempted to merge into the lanes.

The truck collided with the semi, which then jack-knifed and both vehicles collided with the concrete truck, pinning the pickup in the middle.

The driver of the pickup was sent to hospital for observation but was not seriously injured.

The drivers of the larger trucks were not hurt.

The eastbound and westbound lanes of the Perimeter were closed, from St. Mary's Road all the way to Lagimodiere Boulevard, for several hours as police investigated and the scene was cleared.

The eastbound lanes were reopened at about 10:30 a.m. and one westbound lane opened soon after.

But there are still closures in some westbound lanes causing traffic delays.

View Perimeter crash in a larger map