Main Street Tunnel Main Street Tunnel The Main Street Tunnel, located in Welland, Ontario, Canada, is an underwater tunnel, carrying Niagara Road 27 and the unsigned designation of Highway 7146 under the Welland Canal. It is named as a part of East Main Street. The structure was built as a part of the Welland By-Pass project. Its construction was relatively easy since, like the Townline Tunnel, it was constructed at the same time as the channel above it and a simple cut and cover. The tunnel was officially opened on May 20, 1972. The tunnel links Highway 406 on the west side of
Channel Tunnel forecast. Working from both the English side and the French side of the Channel, eleven tunnel boring machines or TBMs cut through chalk marl to construct two rail tunnels and a service tunnel. The vehicle shuttle terminals are at Cheriton (part of Folkestone) and Coquelles, and are connected to the English M20 and French A16 motorways respectively. Tunnelling commenced in 1988, and the tunnel began operating in 1994. In 1985 prices, the total construction cost was £4.65 billion (equivalent to £ billion in 2015), an 80% cost overrun. At the peak of construction 15,000 people were employed with daily expenditure