2.1Defining Rapid Transit Modes

The technologies which have had the most profound effects on human life are usually simple.Freeman Dyson, physicist, 1923–

Public transportation includes all publically accessible transportation services that convey people in common vehicles from one place to another. These services generally run on fixed routes at regularly scheduled intervals. Rapid transit is a form of public transportation on a fixed route that includes features that dramatically improve the speed, capacity, reliability, and quality of the service.

BRT is:

... a bus-based rapid transit system that can achieve high capacity and speed at relatively low cost by combining segregated bus lanes that are typically median aligned, off-board fare collection, level boarding, bus priority at intersections, and other quality-of-service elements (such as information technology and strong branding).BRT Standard, 2015

Five essential elements put the “rapid” in bus rapid transit:

  • Physically separated bus lanes allow buses to avoid congestion;
  • Stations and bus lanes aligned to the center of the street to avoid being delayed by turning vehicles and vehicles dropping off passengers or goods;
  • Fares collected off the bus, to avoid delays caused by passengers paying on board;
  • Boarding from a platform level with the bus floor to make boarding faster, and so that people in wheelchairs or with strollers can roll directly onto the vehicle;
  • Turn restrictions and bus priority at intersections to reduce delay at intersections from red signals.

BRT corridors consist of dedicated, physically demarcated bus lanes that are aligned to the center of a street or a functionally equivalent configuration for the majority of the corridor. They also include one or more of the other three essential elements described above. A more detailed discussion of what constitutes a BRT corridor can be found in the BRT Standard (http://brtstandard.org).

Light-Rail Transit (LRT): a rail-based rapid transit system that uses predominantly exclusive, but not grade-separated, rights-of-way. Like BRT systems, LRTs can have a wide range of passenger capacities and performance characteristics. These capacities and performance characteristics are for the most part driven by the same essential elements that are critical to BRT system performance. These essential elements are defined in the BRT Standard (http://brtstandard.org) and will be discussed in this guide at length. If a rail system were to operate (as some do) in mixed traffic, on the curb lane, with turning movements allowed across it, where passengers have to pay the driver, and passengers need to step up into the vehicle rather than boarding at level, the operating characteristics of the system would be similar to those of a normal bus service, as opposed to an LRT. Conversely, an LRT that operates with prepaid boarding, has a dedicated right-of-way, operates in the central median of the right-of-way, and has all of the other elements of Gold Standard BRT, is likely to provide better service and operate more as a rapid transit system. As such, the BRT Standard technical committee has approved the limited use of the BRT standard to also rate LRT systems, with certain specific caveats ( BRT Standard, p. 55).

Heavy Rail Transit (HRT): an electric rail-based public transport system, often referred to as “Metro,” with high-passenger-capacity rail cars that generally preclude sharp turning movements and require a high platform to board. As such, they cannot generally be operated in normal street conditions, and hence require grade-separated rights-of-way. HRT systems have off-board fare collection, operate within a single built-up urban area with regular station spacing, and provide all-day bidirectional service with regular frequencies. For the purposes of the BRT Planning Guide, HRT will include systems described as commuter rail and metros that align with the above definition. As the vehicles cannot operate on normal streets, many elements recognized as critical to BRT systems do not apply to HRT systems. Though most HRT systems would probably rank “Gold” under the BRT Standard, the BRT Standard Technical Committee has not authorized the use of the BRT Standard for rating HRT systems.

For the purposes of this Planning Guide, what distinguishes LRT from HRT is that it operates for at least part of the transit corridor on normal streets and uses shorter train sets with lower capacities. As such, LRT tends to have flexible bodies capable of tighter turning radii than HRT systems and tends to have floors closer to street level than HRT vehicles. This guide includes in the definition of LRT both systems that are generally referred to as “LRTs” as well as some streetcars and trams.

Monorail: a rail-based public transport system composed of a single rail, usually elevated and thus grade separated. What differentiates the monorail from LRT of HRT is that monorail trains are wider than the guideways that support and guide them. Monorails are only mentioned in passing in this guide, as they are very expensive to build given their carrying capacity. Monorail is not a viable mass transit solution. Note that the definitions above were adapted from the Transportation Research Board and the American Public Transportation Association.