This addition is frequently referred to as the Bayview Extension. It was constructed as part of the Don Valley Parkway project, and necessitated the removal of "Sugarloaf Hill" directly north of the Bloor Street Viaduct. The extension fulfilled the "central spoke" in the building of the "Don Valley Roadway" as proposed in the 1940s. A route through the ravine to St. Clair Avenue was replaced with the present route which stays within the Don Valley proper. With the creations of the Corktown Common in 2013, the southern end of the Bayview Avenue Extension now terminates at Mill Street.