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June 11, 2009
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APTA > Industry Information > Transit Statistics > Rail Statistics  

Rail Definitions

Rail transit services exist in over 50 metropolitan areas and small cities, and the number grows almost yearly.

A mode is the system for carrying transit passengers described by specific right-of-way, technology and operational features.  The most common rail modes are:

Commuter rail (also called metropolitan rail, regional rail, or suburban rail) is an electric or diesel propelled railway for urban passenger train service consisting of local short distance travel operating between a central city and adjacent suburbs.  Service must be operated on a regular basis by or under contract with a transit operator for the purpose of transporting passengers within urbanized areas, or between urbanized areas and outlying areas. Such rail service, using either locomotive hauled or self propelled railroad passenger cars, is generally characterized by multi-trip tickets, specific station to station fares, railroad employment practices and usually only one or two stations in the central business district.  Intercity rail service is excluded, except for that portion of such service that is operated by or under contract with a public transit agency for predominantly commuter services, which means that for any given trip segment (i.e., distance between any two stations), more than 50% of the average daily ridership travels on the train at least three times a week.

Heavy rail (metro, subway, rapid transit, or rapid rail) is an electric railway with the capacity for a heavy volume of traffic. It is characterized by high speed and rapid acceleration passenger rail cars operating singly or in multi-car trains on fixed rails; separate rights-of-way from which all other vehicular and foot traffic are excluded; sophisticated signaling, and high platform loading.  If the service were converted to full automation with no onboard personnel, the service would be considered an automated guideway.

Light rail (streetcar, tramway, or trolley) is lightweight passenger rail cars operating singly (or in short, usually two-car, trains) on fixed rails in right-of-way that is not separated from other traffic for much of the way.  Light rail vehicles are typically driven electrically with power being drawn from an overhead electric line via a trolley or a pantograph.

Other modes are:

Aerial tramway is an electric system of aerial cables with suspended powerless passenger vehicles.  The vehicles are propelled by separate cables attached to the vehicle suspension system and powered by engines or motors at a central location not on board the vehicle.  Only two such transit operations exist in New York City and at Mountain Village, CO.  All other aerial tramways are at ski areas or at tourist sites.

Automated guideway transit (personal rapid transit, group rapid transit, people mover) is an electric railway (single or multi-car trains) of guided transit vehicles operating without an onboard crew. Service may be on a fixed schedule or in response to a passenger activated call button.  The places with automated guideways are Detroit, MI, Indianapolis, IN, Jacksonville, FL, Las Colinas, TX, Miami, FL, and Morgantown, WV.  Automated guideways in non-transit settings such as airports and hospital campuses are more common.

Cable car is an electric railway with individually controlled transit vehicles attached to a moving cable located below the street surface and powered by engines or motors at a central location not on board the vehicle.  Only one cable car operation exists in San Francisco, CA.

Inclined plane is a railway operating over exclusive right-of-way on steep grades (slopes) with powerless vehicles propelled by moving cables attached to the vehicles and powered by engines or motors at a central location not on board the vehicle. The special tramway type of vehicles have passenger seats that remain horizontal while the undercarriage (truck) is angled parallel to the slope.  Chattanooga, TN, Dubuque, IA, Johnstown, PA, and Pittsburgh, PA (2 inclines) are the only places with inclines used in regular transit service.

Monorail is an electric railway of guided transit vehicles operating singly or in multi-car trains. The vehicles are suspended from or straddle a guideway formed by a single beam, rail, or tube.  Only two transit monorails exist in Las Vegas, NV and Seattle, WA.  Their most common use is in the non-transit settings of amusement parks.  If the trains do not have an onboard crew, they are considered automated guideways.

Types of Service

Local service, in the rail context, means trains stop at every station on a route.  For light rail and cable cars operating on city streets, local service would be analagous to local bus service, where stops are every block or two apart.

Most aerial tramway, automated guideway, inclined plane, and monorail routes are one mile or less long.  New York City Transit also has a few very short heavy rail shuttle lines, and most heritage trolley lines are also only a few miles long. Some of these operations may operate in a loop and connect, often at a transfer center or rail station, to major routes for travel to more far-flung destinations

Express service speeds up longer trips, especially in major metropolitan areas during heavily-patronized peak commuting hours, by operating long distances without stopping.  In New York, Chicago, and other areas, express trains even have separate tracks for at least part of their routes.

Limited-stop service is a hybrid between local and express service, where not all stations and stops are served.  An example is a pair of closely-spaced trains that both stop at the most heavily-patronized stations on a line.  For the other stations, the first train stops at every other station, while the following train stops at the stations missed by the first train.

Types of Vehicles

Although most service is operated with vehicles purchased new, a small proportion is operated by vehicles rehabilitated or rebuilt when they are 10 to 20 years old.

Rehabilitation is the rebuilding of revenue vehicles to original specifications of the manufacturer.  Rebuilding may include some new components but has less emphasis on structural restoration than would be the case in a remanufacturing operation, focusing on mechanical systems and vehicle interiors.

An aerial tramway car is an unpowered passenger cabin suspended from a system of aerial cables and propelled by separate cables attached to the vehicle suspension system.  Engines or motors at a central location, not on board the vehicle, power the cable system.

An automated guideway car is a guided passenger car operating under a fully automated system without an onboard crew.  One type is a downtown people mover, which operates on a loop or shuttle route within the central business district of a city.

A cable car is a streetcar type of passenger car operating by means of an attachment to a moving cable located below the street surface and powered by engines or motors at a central location not on board the vehicle.

A commuter rail car is a commuter rail mode passenger car--either an unpowered passenger coach that is pulled or pushed by one or more locomotives, or a self-propelled passenger car that has an onboard power source or that draws power from overhead electric wires.  A large proportion of commuter rail cars are double-decked with upper and lower seating levels.

A locomotive is a power unit vehicle that does not carry passengers that is used to pull or push commuter rail passenger coaches.  Most locomotives use diesel fuel or are powered by overhead electric wires or an electrified third rail.  A small number are dual-mode and can operate either as a diesel or electric vehicle.

A heavy rail car has motive capability, is driven by electric power taken from a third rail or (rarely, overhead wires), and is usually operated on exclusive right-of-way.

An inclined plane car is a special type of passenger car operating up and down slopes on rails via a cable mechanism.

A light rail car (or streetcar, tram, or trolley car) has motive capability, is usually driven by electric power taken from overhead lines, and usually operates much or all of its route on non-exclusive right-of-way.  Sometimes older cars are refurbished (vintage trolley cars) or newer cars are built to look like older cars (heritage trolley cars).

A monorail car is a guided passenger car operating on or suspended from a single rail, beam or tube.


A station is a public transportation passenger facility.

An accessible station is a station that provides ready access, and does not have physical barriers that prohibit and/or restrict access by individuals with disabilities, including individuals who use wheelchairs.

An accessible vehicle is a public transportation revenue vehicle that does not restrict access, is usable, and provides allocated space and/or priority seating for individuals who use wheelchairs.

Historically-protected vehicles, such as the San Francisco cable cars, have been exempted from accessibility regulations.

Rail cars accommodate wheelchair-bound and other riders who cannot climb steps in several different manners:

Street-level boarding is used primarily by light rail and cable car lines that stop on the street rather than at stations.  Either a low-floor car with a retractable ramp or a high-floor car with a retractable lift would be required.

Low-level platforms are generally about 12-18 inches above track level and are used primarily by some commuter rail and light rail lines.  Either a low-floor car with a retractable ramp or a high-floor car with a retractable lift can be used.  Alternatively, the platform can be level with the car floor or the platform may have a lift, ramp, or elevated mini-platform.

High-level platforms are generally 18-36 inches above track level and are used primarily by heavy rail, automated guideway, and some commuter rail lines.  Only high-floor cars can be used.  Platforms can be level with car floors, the cars could have a lift or a ramp, or the platform could have a lift, ramp, or mini-platform.

Some commuter rail and light rail lines use a mixture of high-level and low-level platforms on the same line.  Typically, all platforms were originally low-level, but the most heavily-used stations have been upgraded to high-level to speed loading and unloading.  In such cases, the cars must have two accessibility options--one for high-level platforms and one for low-level platforms.

Other rail modes may use any of the accessibility arrangements.

Fixed Guideways

All rail services are classified as fixed guideways.

A Fixed Guideway is a mass transit facility using and occupying a separate right-of-way or rail for the exclusive use of mass transportation and other high-occupancy vehicles; or using a fixed catenary system usable by other forms of transportation.

Fixed guideways are generally on the surface, but about half of heavy rail mileage and short distances of other types of rail are in tunnel or elevated.

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