A 63-year-old Windsor truck driver has been airlifted to hospital and is in critical condition after a rollover on Highway 401.

It was about 3 p.m. on Tuesday afternoon when a westbound transport left the road, rolled down the hill on the north side of the CSX overpass and came to rest on its passenger side in a ditch just west of Communications Road in Chatham-Kent.

No other vehicles were involved.

The westbound lanes of the 401 at Highway 40 were closed for several hours, but one lane was re-opened. Police planned to close the highway again from 6:30 to 8:30 p.m.

It's not yet known why the truck veered off the highway and the investigation continues.