Officers say around 1:30 Tuesday afternoon, an eastbound tractor trailer’s front tire blew out, causing it to collide with a passing vehicle.
Police say both vehicles crossed through the centre median, blocking both westbound lanes of the highway near Charing Cross Road.
While no injuries were reported, an OPP officer witnessed the collision and was about to stop westbound traffic from being involved in a head-on collision.
The highway was closed for several hours, but officers say it has since re-opened.