Passenger rail terminology

Various terms are used for passenger rail lines and equipment. Unfortunately the usage of these terms differs substantially between areas.

Rapid transit

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, omnibuses, 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.

ubway

"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 and Latin American cities.

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. Also, the Buffalo Metro Rail is referred to as "the subway", while it uses light rail equipment and is in a pedestrian mall downtown. 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.

In London the colloquial term ‘tube’ refers to the London Underground and is the most common word used for the underground system, and it is used by Transport for London the local government body responsible for most aspects of the transport system throughout Greater London. [ [http://www.tfl.gov.uk/modalpages/2625.aspx London Underground: Tube travel information] website of Transport for London] The Glasgow metro system is known as the Glasgow Subway or colloquial as "the subway". The word "Metro" is not usually used in London or Glasgow to refer to those cities' metros, but it is used in and around Newcastle upon Tyne to refer to the Tyne and Wear Metro.

Paris, Rome, Madrid and Moscow all have metro systems which are called metro in French, Italian, Spanish and Russian. [ [http://www.parisvisite.com/fr/Transports_Metro.php Transports Metro] ] [ [http://www.metroroma.it/MetroRoma/HTML/EN MetroRoma - Home] ] [ [http://www.metromadrid.es/ Metro de Madrid] ]

U-Bahn and S-Bahn

The term metro is not usually used to describe metro systems in Germany, Austria and the German speaking cantons of Switzerland, as the Germans use the term "U-Bahn" — a shortening of "Untergrundbahn", meaning "underground railway" — and S-Bahn — an abbreviation for the German "Stadtschnellbahn" (fast city train). So for example in Berlin the mostly underground system is know as the Berlin U-Bahn and it is integrated with the mostly above ground system is known as the Berlin S-Bahn. BVG, the operators of the Berlin U-Bahn system describe the U-Bahn as "the largest metro system in Germany" [ [http://www.bvg.de/index.php/en/Bvg/Index/folder/70 The Berlin metro (U-Bahn)] ] and the S-Bahn system as "urban rail system" [ [http://www.bvg.de/index.php/en/Bvg/Detail/folder/696/id/2828/nb/1/name/The+urban+rail+system+%28S-Bahn%29 The urban rail system (S-Bahn)] ] .

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.

*Chicago 'L' The best known elevated transit system in the United States.Fact|date=November 2007
*Liverpool Overhead Railway This was the United Kingdom's only true elevated railway.
*SEPTA's Market-Frankford Line is elevated except for the portion running through center city, and is sometimes referred to as the "El".

At-grade urban rail transit

Tram, streetcar, trolley

The terms "tram", "streetcar" and "trolley" refer to most forms of common carrier rail transit that run entirely or partly on streets, providing a local service and picking up and discharging passengers at any street corner, unless otherwise marked. While tram or "tramway" are widely used worldwide, the term used varies in English, with "streetcar" and "trolley" most common in North America, while "tram" predominates elsewhere.

"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. 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.

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 [http://www.minneapolis.org/travelinfo/trolley.asp/ RiverCity Trolley] in Minneapolis, Minnesota.

More specific terms for some tram technologies include "horsecar", "heritage streetcar", 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.

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 passengers 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 unfavorable toward 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.

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 Millennium Station 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, "interurban" 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.

Heavy rail

Heavy rail refers to regional rail and intercity rail services as distinct from other rapid transit or light rail modes, such as when referring to National Rail services in London.

Heavy rail can also refer to rapid transit services in North America, when referring to the heavier passenger loadings compared to light rail systems [ [http://www.apta.com/research/stats/rail/definitions.cfm American Public Transport Association] definition of heavy rail] , but distinct from commuter rail and intercity rail systems.

Regional rail and Commuter rail

Regional rail usually provides rail services between towns and cities, rather than purely linking major population hubs in the way inter-city rail does. In North America particularly, the term "Regional Rail" is synonymous with commuter rail.

Regional trains are usually all seated and provide luggage space, although they seldom have all the amenities of inter-city trains such as a buffet or dining car. Since their invention, the distinction between regional and long-distance rail has also been the use of multiple unit propulsion, with longer distance trains being locomotive hauled, although development of trains such as the British Rail Class 390 have blurred this distincion. Shorter regional rail services will still usually be operated exclusively by multiple units where they exist, which have a shorter range and operate at lower average speeds than services on Inter-city rail networks. Not using a locomotive also provides greater passenger capacity in the commuter role at peak periods.

British Rail, during sectorisation, did once create a "Regional Railways" subsidiary, however this was so named to differentiate it's 'all other regions' lines from the other sectors Network SouthEast, which heavily focused on commuters services to London terminal stations but operated rail services across the South East region, and the Inter-City sector which operated long distance services.

Intercity, Corridor and Long-Distance

Intercity rail refers to passenger routes which connect two or more distinct cities. It is usually used to refer to routes which interconnect different major conurbations, not used to refer to lines which connect a major city with its suburbs, though this is not a hard-and-fast distinction.

In the US, "Corridor" services refer to routes connecting relatively nearby cities, where one city can be visited from another without staying overnight. "Long-Distance" refers to routes which cover vast rural distances.

Rail Terminology with regard to Speed

Non-high-speed rail: Less than 200 km/h

The vast majority of passenger trains, and almost 100% of freight trains are of this category.

High-speed rail: 200 km/h – 550 km/h

There is no globally accepted standard separating high-speed rail from conventional railroads; however a number of widely accepted variables have been acknowledged by the industry in recent years. Generally, high-speed rail is defined as having a top speed in regular use of over 200 km/h (125mph). Although almost every form of high-speed rail is electrically driven via overhead lines, this is not necessarily a defining aspect and other forms of propulsion, such as diesel locomotives, may be used. A definitive aspect is the use of continuous welded rail which reduces track vibrations and discrepancies between rail segments enough to allow trains to pass at speeds in excess 200 km/h. Track radius will often be the ultimate limiting factor in a train's speed, with passenger discomfort often more imminent than the danger of derailment. Depending on design speed, banking and the forces deemed acceptable to the passengers, curves often exceed a 5 kilometer radius. Although a few exceptions exist, zero grade crossings is a policy adopted almost worldwide, with advanced switches utilizing very low entry and frog angles. Magnetic levitation trains fall under the category of high-speed rail due to their association with track oriented vehicles; however their inability to operate on conventional railroads often leads to their classification in a separate category.

In the US, "high speed rail" is often used to describe services faster than 100mph. This is because almost no regular services in the US exceed 80 mph, which is low by international standards.

Very high-speed rail: 550 km/h – 800 km/h

A number of both technological and practical variables begin to influence trains in the vicinity of 500-600 km/h. From a practical standpoint, very-high-speed trains are those whose velocity will exceed that of most propeller-driven aircraft. Technologically the limitations are by no means beyond reach, however conventional trains begin to encounter several physical obstacles, most notably track damage and pantograph limitations. It is important to note that the current world record for rail vehicles is held by the TGV V150 set on 15 April 2007 at 574.8 km/h, and conventional trains may indeed eventually reach into very high-speeds. However, based on current and foreseeable technology, these speeds will more than likely be reached predominantly by maglev trains. The two most prominent maglev trains are the Transrapid with a maximum speed of 550 km/h; and the JR-Maglev MLX01, which holds the world land speed record for railed vehicles at 581 km/h.

Ultra high-speed rail: 800 km/h – 1000 km/h

Ultra high-speed rail is a projected classification into the far future of rail transportation. These speeds are based solely on their potential to compete directly with commercial subsonic jet aircraft. Regardless of technological parameters, the track for such a train and anything faster would more than likely require turn radii of significantly higher proportions than current dimensions, essentially preventing anything but a direct line between terminals. Such trains are extremely unlikely in the current or near future.

Greater than 1000 km/h

Depending on the aerodynamic design of the vehicle and various ambient atmospheric conditions, a train would begin to exhibit transonic airflow in the vicinity of Mach .8 (988 km/h) and higher. From a modern perspective, this is essentially the realistic maximum speed of trains as they are known today. This is because the Prandtl-Glauert singularity would cause catastrophic damage to the vehicle as the sound waves reflected off of the ground, potentially blasting the train into the air. Trains could exceed this speed significantly, were they vactrains.

References

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