Highway 404, HOV Tunnel at Highway 401 | Toronto Contract consisted of widening of Hwy 404 Southbound from Sheppard Ave. to Hwy 401 Westbound including the construction of a tunnel structure under Highway 404. It included construction of reinforced earth retaining walls and concrete retaining walls, permanent and temporary structure infills, high mast lighting, concrete base and hot mix paving. Construction of the contract required extensive traffic staging over the course of 2 construction seasons.