A driver says he's lucky to be alive after a tire smashed through his windshield as he drove down a Toronto highway, in an incident captured on video.

In the description of his video posted on YouTube, Andrew Sukhdeo says he was travelling westbound on Highway 401 approaching Salem Road when "a tire flew over the median and smashed into my car. I'm lucky to be alive."

It's not clear what caused the tire to come loose.