Subways and Light Rapid Transit

Subways and Light Rapid Transit

Subways and Light Rapid Transit Subways, sometimes referred to as heavy rail transit, are urban, electric, rapid-transit lines capable of carrying large numbers of people: between 20 000 and 40 000 passengers per hour in each direction. No other traffic is permitted to interfere with the separate rights-of-way of subway trains. Most subways are underground, hence the name, but portions can be at grade (ground level) with suitable fences or barriers, depressed in a cut without covering, or even elevated. Power is supplied to the trains by means of a "third rail," although overhead wire is sometimes also used. Station platforms are built at the same level as the floor of the subway car, eliminating steps for entry and exit. Fare collection occurs in stations rather than on vehicles, and a full signal system is used for operation to ensure safety. Light rail transit is simpler and less costly than a subway but also has less capacity, between 8000 and 20,000 passengers per hour in each direction. The vehicles are lighter than subway cars and are essentially streetcars. The right-of-way may be only partially separated, with grade crossings and portions of a line operating in mixed traffic on the street. Power collection is from overhead wires; passenger loading may use platforms or steps or both, and fare collection can be either on board or at the stations. Light rail systems are usually, but not always, signalized (see STREET RAILWAYS).

Canada has 2 subway systems, in Toronto and Montréal. Toronto had the first system, with the Yonge St line (7.4 km in length) opening in March 1954. The Toronto system was expanded in stages; by 1998 it was operating 640 subway cars along 55 km, serving 66 stations on 3 major lines. The Montréal system opened its initial portion in 1966, with 3 lines, 26 stations and a total length of 22 km. At the end of the 1990s it was 60.85 km long and had 65 stations and 4 lines. The Toronto subway cars are 3.15 m in width, with steel wheels running on rails. The Montréal cars are 2.5 m in width, and use rubber tires.

Other cities operate light rapid transit (or light rail transit) systems. Edmonton was the first North American city with a population under 1 million to build an LRT system. It opened in 1978, prior to the Commonwealth Games, and consisted of 1.6 km of track under the downtown area. It expanded 4 times in the 1980s and 1990s and now has 10 stations, 6 of them underground, and operates 37 light rail vehicles over a 12.3 km route, serving an average of 36 000 weekday riders. The LRT tracks cross the North Saskatchewan River on the Dudley B. Menzies Bridge, which was the first segmental precast concrete structure built in western Canada. The capacity is 6800 passengers per hour per direction on a fully separate right-of-way. The Calgary LRT line, opened in 1981, is 22 km in length, and has 25 stations. This LRT facility has both at-grade and below-grade crossings at road intersections and uses railway-type signals and lights giving the LRT vehicles priority. Line capacity is 9400 passengers in the peak direction per hour. The design capacity of the Edmonton and Calgary lines is much higher than present usage. Both the Edmonton and Calgary systems use 2-section, 23 m articulated LRT vehicles designed and built in West Germany. Ontario's Urban Transportation Development Corporation has designed an advanced LRT technology using automated train control, lightweight cars and linear-induction motors with steerable trucks to reduce noise levels. Apart from the vehicle technology and totally grade separated right-of-way, the major difference of this system is its capacity, which is between those of LRT and subway. A 21.4 km line using the ALRT technology opened in 1986 in Vancouver, and a similar line of some 6.5 km in length opened in Toronto in March 1985.