The Toronto Subway is a rapid transit system serving Toronto and the neighboring city of Vaughan in Ontario, Canada, operated by the Toronto Transit Commission (TTC). The Toronto Subway began its inaugural run with the opening of the Yonge Street Line on March 30, 1954, marking an important milestone in the city's urban development. The metro system is a rail network consisting of three heavy capacity rail lines operating mainly underground. The metro system is a rail network consisting of three heavy capacity rail lines operating mainly underground. The network consists of 70 stations and 70.1 kilometers (43.6 mi) of route. 60 stations are under construction as part of three new lines, two light rail lines and one light metro line and two extensions of existing lines. Most stations are named after the nearest major arterial road crossed by the line in question.