Passenger rail terminology
Various terms are used for
passenger rail lines and equipment. Unfortunately the usage of these terms differs substantially between areas.
Originally, the term
rapid transit was used in the 1800s to describe new forms of quick urban
public transportation that had a
right-of-way separated from street traffic. This set rapid transit apart from
horsecars,
trams,
streetcars, es, and other forms of public transport.
Though the term was almost always used to describe
rail transportation, other forms of transit were sometimes described by their proponents as rapid transit, including local
ferries in some cases.
The term
bus rapid transit has recently come into use to describe
bus lines with features to speed their operation. These usually have more characteristics of
light rail than rapid transit.
Subway
Subway used in a transit sense refers to either a
rapid transit system or (rarely) a
light rail/
streetcar system that goes underground. The term may refer only to the underground parts of the system, or to the full system.
Subway is most commonly used in the
United States and some parts of
Canada, though the term is also used elsewhere, such as to describe
the subway line in
Glasgow,
Scotland and in translation of system names or descriptions in some
Asian cities into and in America Latina too.
English.
Some lines described as
subway use
light rail equipment. Notably, the
Newark City Subway and Boston's
Green Line, each about half underground, originated from fully surface
streetcar lines. Sometimes the term is qualified, such as in
Philadelphia, where trolleys operate in an actual subway for part of their route and on
city streets for the remainder. This is locally styled
subway-surface.
In some cities where
subway is used, it refers to the entire system; in others, only to the portions that actually are underground. Naming practices often select one type of placement in a system where several are used; there are many
subways with above-ground components, and on the other hand, the
Vancouver SkyTrain and
Chicago `L' include underground sections.
Interestingly, when the
Boston subway was originally built, the
subway label was only used for sections into which
streetcars (trams) operated, and the rapid transit sections were called
tunnels. Also, in some countries,
subway refers to systems built under roads (such as the
Glasgow Subway or London's
Metropolitan Line) and the informal term
tube is used for the deep-underground tunnelled systems (such as London's
Piccadilly Line) - in this usage, somewhat technical nowadays and not used much in London,
underground is regardless the general term for both types of system.
Bus subways are uncommon but do exist, though in these cases the non-underground portions of route are not called subways.
Seattle, Washington has a
bus subway downtown, in which dual-mode trolleybuses can operate on overhead wires when in the subway and via
internal combustion when outdoors. Bus subways are sometimes built to provide an exclusive right-of-way for
bus rapid transit lines, such as the
MBTA Silver Line in Boston. These are usually called by the term
bus rapid transit.
'Subway' outside the USA, and especially in Europe often refers to underground pedestrian passageways linking large road interconnections that are often too difficult or dangerous to cross at ground level.
Underground, Metro and Tube
The usage of
underground is very similar to that of subway, describing an underground train system. Similarly,
Metro usually refers to
rapid transit.
Many
Germanic languages use the term U-Bahn, meaning
underground railway, while many others in Europe use
Metro. In
London, the word
Metro most commonly refers to the
London Underground, not the
Docklands Light Railway, or frequent
suburban National Rail train services which are referred to as trains, over ground trains, national/local trains or crossrail services.
The colloquial term ‘tube' refers to the
London Underground and is the most common word used for the underground system.
The
Brussels Metro has three traditional rapid transit lines and two
premetro lines which run trolleys but have enough width to be eventually converted to the bigger metro standards if the traffic warrants it.
Elevated
Elevated is a shortened form of
elevated railway, a
railway built on supports over other rights of way, generally city streets. They are also called
els.
*
Liverpool Overhead Railway This was the United Kingdom's only true elevated railway.
Streetcar
The U.S. term
streetcar is generic to most forms of
common carrier rail transit that runs or has run on streets, providing a local service and picking up and discharging passengers at any street corner, unless otherwise marked.
More specific terms for some streetcar technologies include
horsecar,
trolley and
cable car.
In the
Tennessee Williams play
A Streetcar Named Desire, the term
streetcar is used
allegorically to refer to
Blanche duBois'
promiscuousness and inability to form permanent relationships, as in the
sarcastic phrase: "Men (or women) are like streetcars. There'll be another one along any minute." There was actually a streetcar line in New Orleans named
Desire Street and simply signed
Desire. It is mentioned in the book and an actual New Orleans streetcar with that signage is seen at the beginning of the
Marlon Brando-
Vivien Leigh film.
Tram
The name
tram is from
Low German traam, meaning the "beam (of a
wheelbarrow)", although some sources claim inaccurately that it is derived from the name of engineer
Benjamin Outram. It is typically used in
Europe to describe any [whatever we decide to call stuff below rapid transit] system.
In the
U.S. the word
tram frequently refers to a
tourist bus with the appearance of a
heritage streetcar,
cable car, or rubber-tired people-mover. They are frequently used for parking lot shuttles at theme parks and major events or transportation within theme parks.
Trolley can sometimes carry similar meaning, as in the
RiverCity Trolley in
Minneapolis, Minnesota. The use of the term
trolley for trams and light rail vehicles is derived from the
trolley pole and connected trolley wheel that was used as an electric current pickup in early systems.
Interurban
In the
U.S.,
interurban refers to a higher-speed
rural streetcar line. Interurbans are all but gone, with two of the remaining (
Norristown High Speed Line,
IRT Dyre Avenue Line) having been upgraded to
rapid transit specifications. The
South Shore Line, which runs from
Chicago's
Randolph Street Terminal to
South Bend, Indiana, has been converted to modern electric rapid-transit operation on the dense corridor between Chicago and
Gary, Indiana but still runs essentially as an interurban through several small towns between Gary and South Bend.
Interurbans sometimes used freight railways rather than building their own track.
In
Australia,
intercity refers to long distance commuter trains such as the routes between
Newcastle and Sydney, between
Brisbane and Gympie, or between
Brisbane and the Gold Coast. Some interurban trains may operate from where suburban lines end, such as
Southern Higlands services between Campbelltown and Goulburn, or between
Ipswich and Rosewood. These do not have the features of "intercity trains" in other parts of the world, such as booked seats and meal services, but are bare commuter trains. They are properly called interurban rather than intercity, although
CityRail refers to its interurban services as "intercity" trains.
Light rail
Light rail is a term coined in the
1970s during the re-emergence of
streetcars/
trams. In general, it refers to streetcar/tram systems with rapid transit-style features. It is named to distinguish it from
heavy rail, which refers to
rapid transit systems as well as heavier
regional rail/
intercity rail.
A few systems such as
people movers and
personal rapid transit could be considered as even "lighter", at least in terms of how many passengers are moved per vehicle and the speed at which they travel.
Monorails are a separate technology.
Light rail systems can typically handle steeper
inclines than heavy rail, and
curves sharp enough to fit within street
intersections. They are typically built in
urban areas, providing frequent service with
multiple-unit trains or single cars.
The most difficult distinction to draw is that between light rail and
streetcar/
tram systems. There is a significant amount of overlap between the technologies, and it is common to classify streetcars/trams as a subtype of light rail rather than as a distinct type of transportation. The two general versions are:# The traditional type, where the tracks and trains run along the streets and share space with road traffic. Stops tend to be frequent, and little effort is made to set up special stations. Because space is shared, the tracks are usually visually unobtrusive.# A more modern variation, where the trains tend to run along their own
right-of-way and are often separated from road traffic. Stops are generally less frequent, and the vehicles are often boarded from a platform. Tracks are highly visible, and in some cases significant effort is expended to keep traffic away through the use of special signaling, and even
grade crossings with gate arms.:At the highest degree of separation, it can be difficult or impossible to draw the line between light rail and
rapid transit, as in the case of
London's
Docklands Light Railway, which would likely not be called
light rail were it not for the contrast between it and the
London Underground.
Many light rail systems — even fairly old ones — have a combination of the two, with both on-road and off-road sections. In some countries, only the latter is described as
light rail. In those places,
trams running on mixed right of way are not regarded as light rail, but considered distinctly as streetcars or trams. However, the requirement for saying that a rail line is "separated" can be quite minimal — sometimes just with concrete "
buttons" to discourage
automobile drivers from getting onto the tracks.
There is a significant difference in cost between these different classes of light rail transit. The traditional style is often less expensive by a factor of two or more. Despite the increased cost, the more modern variation (which can be considered as "heavier" than old streetcar systems, even though it's called
light rail) is the dominant form of new
urban rail transit in the
United States. The
Federal Transit Administration helps to fund many projects, but as of
2004, the rules to determine which projects will be funded are biased against the simpler streetcar systems (partly because the vehicles tend to be somewhat slower). Some places in the country have set about building the less expensive streetcar lines themselves or with only minimal federal support. Most of these lines have been
"heritage" railways, using refurbished or replica streetcars harkening back to the first half of the
20th century. However, a few, such as the
Portland Streetcar, use modern vehicles. There is a growing desire to push the Federal Transit Administartion to help fund these startup lines as well.
Light rail is generally powered by electricity, usually by means of
overhead wires, but sometimes by a
live rail, also called third rail (a high voltage bar alongside the track), requiring safety measures and warnings to the public not to touch it. In some cases, particularly when initial funds are limited,
diesel-powered versions have been used, but it is not a preferred option. Some systems, such as
AirTrain JFK in New York City, are automatic, dispensing with the need for a driver; however, such systems are not what is generally thought of as light rail, crossing over into
rapid transit.
Automatic operation is more common in smaller
people mover systems than in light rail systems, where the possibility of grade crossings and street running make driverless operation of the latter inappropriate.
Heavy rail sometimes refers to
rapid transit, but sometimes refers to
regional rail (also known as "commuter rail") and
intercity rail.
See
Regional rail.
