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.[1]
Ferries
Prior to the construction of the causeway, Cape Breton Island was connected to the mainland by separate railway car and motor vehicle ferries.