 King 's Highway 140 , commonly referred to as Highway 140 , is a provincially maintained highway in the Canadian province of Ontario . The highway connects Port Colborne near Lake Erie with Highway 406 in Welland , via the Main Street Tunnel . It was constructed in the early 1970s as part of the Welland Bypass project of the Welland Canal , which resulted in the severance of several highways and rail lines . Opened to traffic in late 1972 , several months following the tunnel , Highway 140 has remained unchanged since , despite growing calls to resign it as an extension of Highway 406 . 
