A car accident on Highway 15 south of Blainville has forced the closure of the highway, causing a monster traffic jam.
The driver of a car lost control, slammed into a sign post, breaking one of the poles.
The driver was taken to hospital with serious, but non-life threatening injuries. A spokesman for provincial police says the highway will have to be closed at least another two hours, until the post can be removed.
Drivers can use Route 117 as a detour.
The cause of the accident is under investigation.
For updates on traffic information, follow @montrealdrive on @cbchomerun.