To start off, let us avoid using term subway, and use the following terms:
(BRT)
Operation of buses mostly on dedicated right-of-ways with stations or stops placed at wider intervals than regular bus operation. In some cases, vehicles may operate on a route that is only partly in BRT and partly in regular operation.
Examples: busway operations by OC Transpo (Ottawa) and Port Authority (Pittsburgh); VIVA Phase 2 will fall into this definition.
Commuter Rail typically consists of a locomotive pulling passenger cars on existing railways, operating at high speeds with gentle starts and stops. Routes are usually 40-80 km long with a terminal in a central business district. Service is generally geared toward morning and evening commutes.
Example: GO Transit's rail operations.
(DMU)
Railway passenger vehicles powered by built-in diesel engines. DMUs can provide similar capacity to LRT without the need for electrification. Electrification adds a cost that is economical for lines needing frequent service. Thus, DMUs are usually a better choice for relatively light traffic situations.
Example: OC Transpo's (Ottawa) O-Train operations with 15 minute minimum headways.
(HRT/Subway)
Heavy Rail is high-speed passenger rail electrically powered generally from a third rail. Heavy rail must operate on an exclusive right-of-way. Service is intended primarily for central city travel, and stations are generally close together. Heavy rail is costly to build and requires large rights-of-way and infrastructure.
Example: of this is the TTC's Subway.
(LRT)
Light rail, considered the modern streetcar, is used mostly in urban areas with significant population centres. Light rail offers flexibility of location because it can be operated in a street as well as a dedicated right-of-way for rapid operation without interference from other traffic.
Examples of this can be seen on this site.
- LRT refers to a rapid transit system using streetcar type vehicles operating on a track infrastructure that does not have to be totally isolated from the public. This means there can be at-grade crossings with traffic and pedestrians, and it may occasionally operate in mixed-traffic situations. An LRT system has a traffic control system that uses driver control and a limited amount of interlocking and automatic signals that includes standard traffic signals.
- Subway refers to a rapid transit system using metro type vehicles operating on a track infrastructure that must be totally isolated from all road and pedestrian traffic with stations limiting the movement of passengers. A Subway system has a traffic control system that uses interlocking and automatic signals along its entire route, and may also have a form of automatic train control.
The light and heavy words in LRT and HRT can be confusing. They tend to refer to passenger capacity. Some confuse it with the rolling stock which is problematic as it is not unusual for an LRV (light rail vehicle) to be heavier than a Subway car. Some think in terms of the rail the vehicles run on, as LRT systems often use lighter grade rail, but not always. Besides, when it comes to heavier rail, that definition can blend HRT with Commuter Rail systems.
As an additional note, systems such as the Scarborough RT, Vancouver's SkyTrain, and London's Docklands Light Railway all fall into the Subway category. Despite these systems having a light-to-intermediate capacity, their need for a totally isolated ROW plus a signalling and control system that supports automatic train control places them in here. Some refer to a system such as these examples as a Mini Subway.
Send questions, comments, and photos hereThis page last updated May 28, 2008