The Canso Causeway (Scottish Gaelic: Cabhsair Chanso)45°38′38″N 61°25′11″W / 45.64389°N 61.41972°W is a 1,385 m (4,544 ft) rock-fill causeway crossing the Strait of Canso, provides access by road to the Atlantic Ocean, to the Gulf of St. Lawrence or Cape Breton Island to the Nova Scotia peninsula.[1]
Its crest thickness is 40 m (130 ft), carrying the two vehicle traffic lanes of the Trans-Canada Highway, Nova Scotia Highway 104 on the mainland side, and Nova Scotia Highway 105 on the Cape Breton side, as well as the single track mainline of the Cape Breton and Central Nova Scotia Railway.
The causeway opened in 1955 after three years of construction. Constructed in an "S" shape, it has a base width of 244 m (801 ft) in waters having a maximum depth of 65 m (213 ft).
Cape Breton Island remains circumnavigable as a result of the 24 m (79 ft) wide and 570 m (1,870 ft) long Canso Canal, which is located at the eastern end of the causeway to allow ship traffic to transit the Strait of Canso. The 94 m (308 ft) Canso Canal Bridge is a swing bridge which carries the road and railway line across the canal.
The word "Canso" is believed to be derived from the Mi'kmaq word kamsok, which means "opposite the lofty cliffs."
On July 2, 2014, it was announced that the Government of Canada would transfer ownership of the causeway to the Nova Scotia provincial government. The federal government will still maintain the Canso Canal and the navigational locks.[2]
The mile long eighty foot wide man-made causeway is known as the deepest in the world