Donald Cousens Parkway

Donald Cousens Parkway, regionally designated as York Regional Road 48 and historically known as the Markham Bypass or Markham Bypass Extension, is a regionally maintained arterial bypass of Markham in the Canadian province of Ontario. The route originally began at Copper Creek Drive in Box Grove, south of Highway 407, and travels north to Major Mackenzie Drive (York Regional Road 25). The southern extension to meet with the Box Grove Bypass was completed and now the name Donald Cousens Parkway applies to the southern section to Steeles Avenue East at the Toronto–York boundary. The route is named for former Markham mayor Don Cousens.

Donald Cousens Parkway and the future connection with Morningside Avenue form the East Metro Transportation Corridor, originally envisioned as a six lane municipal expressway during the 1970s. During the mid-1990s, the Ministry of Transportation of Ontario (MTO) conducted studies and identified the need for the corridor by 2011. Although York had intended for a continuous alignment, the City of Toronto has opposed the direct connection between Morningside and Donald Cousens Parkway.

Construction of the route began in 2002 north of 16th Avenue. In 2004, an interchange with Highway 407 was constructed; it opened along with a connection to Highway 7 in 2005.