Southbound traffic is moving again on Highway 400 after a morning multi-vehicle collision south of Barrie closed the highway for almost three hours.

Just after 6 a.m. Monday, Ornge air ambulance dispatched a helicopter to the intersection of Highway 400 at Highway 89. After 7 a.m., police were allowing large vehicles such as buses and trucks pulling trailers through but the rest of traffic remained at a standstill.

The highway has since re-opened to southbound traffic, but the morning closure has led to a backlog on Hwy. 400 and many alternate routes.