Quebec Autoroute 540

Autoroute 540 was a short spur route that connected Autoroute 20 to Autoroute 40, providing a direct freeway link from Windsor, Ontario to Quebec City, Rivière-du-Loup, and points east through A-40, as A-20 currently has several at-grade intersections in Vaudreuil-Dorion as a multi-lane divided road. A-540 was the shortest numbered Autoroute.
In 2006, construction began to extend Autoroute 30 north of the St. Lawrence River to the existing junction with Autoroute 540 and Autoroute 20, necessitating reconstruction of that interchange. Once that was completed in December 2012, A-540 was annexed and re-designated as an extension of Autoroute 30, while the old alignment of A-30 south of Salaberry-de-Valleyfield was renamed Autoroute 530. This made the expanded A-30 a ring road serving the southwestern part of the Montreal metropolitan area.

Wikipedia