Only lack of 300km of Gulf of St. Lawrence North Shore highway and the missing Strait of Belle Isle fixed link now prevent a continuous Trans-Canada Highway, and 500,000 Newfoundland residents, their visitors and commercial vehicles from entering or leaving the Island except by ship or aircraft. These road travel gaps now cost Newfoundlanders in ferry tolls and lost time, import-export shipping costs, weak tourism, and no Labrador hydropower, an estimated $290 million/year. A rail tunnel across the Strait could carry all types of road vehicles, Labrador hydropower and piped fuel, and also significantly strengthen unity in both Canada and its easternmost Province. Its capital plus operating cost, subject to much-needed detailed study, can be only $70 million/year for 40 years. Due to potential water inflows a bored rail tunnel may not be viable. Immersed tunnels consist of reinforced waterproof segments built on land, floated over and then lowered into a seabed excavated trench, joined to adjacent segments, and protected from icebergs and ships with a stone cover. The world has over 100 immersed tunnels. Like the bridge to Prince Edward Island, investors will tender to build, own, and operate the tunnel with income from tolls and government aid equal to current ferry subsidies for an agreed time, and then transfer it, debt free, to public ownership. Because a North Shore road and Strait of Belle Isle tunnel will provide a continuous Trans-Canada Highway and other vital benefits, both projects deserve the earliest possible federal-provincial studies.