Plane makes emergency landing on Quebec highway

He had just taken off. This highway runs parallel and adjacent to the only runway at the Mascouche airport. If he had to put down that quickly, and wasn't able to make it back to the runway, then the issue must have been very serious. Local news reports tell of engine problems. Glad no injuries or worse resulted.

There's a small GA airport nearby, maybe trouble just after take-off or before landing.

Looks like a Cessna. Did he mean to pull back on the throttle (reduce power) and accidentally pull back on the mixture control? It has happened before.

Another photo here:

http://www.montrealgazette.com/news/Small+plane+makes+emergency+landing+Highway/10101222/story.html

The aircraft is a Cessna 150L not an ultra-light