Crews were called in to right a transport truck after it rolled over on Highway 427, blocking two lanes of traffic.

The truck rollover happened on the ramp linking southbound 427 to westbound Highway 401 at approximately 4:45 a.m. on Tuesday.

Diesel fuel was spilled during the crash.

It is not yet known what caused the rollover, but police said the northbound and southbound 427 express lanes were closed at the 401 for an investigation and cleanup.

The lanes have since reopened.