Police have closed the Thorold-Highway 20 overpass at Highway 406 in both directions following a serious motor vehicle collision.
The collision happened Friday afternoon and involved a motorcycle and a vehicle.
Northbound and Southbound ramps to and from 406 to highway 20 are also closed.
The extent of the injuries of the people involved is unknown at this time.
There is no estimated time of re-opening as the investigation continues.