Commuter rail, also called suburban rail, is a passenger rail transport service that primarily operates between a city center, and the middle to outer suburbs beyond 15 km (10 miles) and commuter towns or other locations that draw large numbers of commuters—people who travel on a daily basis. Trains operate following a schedule, at speeds varying from 50 to 200 km/h (30 to 125 mph). Distance charges or zone pricing may be used.
Non-English names include Treno suburbano in Italian, Cercanías in Spanish, Rodalies in Catalan, Nahverkehrszug in German (and in most larger cities S-Bahns though these trains may include city centre metro sections and/or circular or partly circular lines), Train de banlieue in French, Příměstský vlak in Czech, Elektrichka in Russian, and Pendeltåg in Sweden. The development of commuter rail services has become popular today, with the increased public awareness of congestion, dependence on fossil fuels, and other environmental issues, as well as the rising costs of owning, operating and parking automobiles.
- being larger
- providing more seating and less standing room, for the longer distances involved
- having (in most cases) a lower frequency of service
- having scheduled services (i.e. trains run at specific times rather than at specific intervals)
- serving lower-density suburban areas, typically connecting suburbs to the city center
- sharing track or right-of-way with intercity or freight trains
- not fully grade separated (containing at-grade crossings with crossing gates)
Train schedule 
Compared to rapid transit (or metro rail), commuter/suburban rail has lower frequency, following a schedule rather than fixed intervals, and fewer stations spaced further apart. They primarily serve lower density suburban areas (non inner-city), and often share right-of-way with intercity or freight trains. Some services operate only during peak hours and others uses fewer departures during off peak hours and weekends. Average speeds are high, often 50 km/h (30 mph) or higher. These higher speeds better serve the longer distances involved. Some services include express services which skip some stations in order to run faster and separate longer distance riders from short-distance ones.
The general range of commuter trains' distance varies between 15 and 200 km (10 and 125 miles). Sometimes long distances can be explained by that the train runs between two or several cities (e.g. S-Bahn in the Ruhr area of Germany) Distances between stations may vary, but are usually much longer compared with urban rail system. In the city center the trains either has a terminal station or pass through the city centre with notably fewer station stops compared with urban rail system. Toilets are often available on board trains and in stations.
Their ability to coexist with freight or intercity services in the same right-of-way can drastically reduce system construction costs. However, frequently they are built with dedicated tracks within that right-of-way to prevent delays, especially where service densities have converged in the inner parts of the network.
Most such trains run on the local standard gauge track. Some light rail systems may run on a narrower gauge. Examples of narrow gauge systems are found in Japan, Switzerland, in the Brisbane (Citytrain) and Perth (Transperth) systems in Australia, in some commuter rail systems in Sweden, and on the Genoa-Casella line in Italy. Some countries, including Finland, India, Pakistan, Russia, Brazil and Sri Lanka, as well as San Francisco (BART) in the USA and Melbourne and Adelaide in Australia, use broad gauge track.
Distinction between other modes of rail 
Metro rail or rapid transit usually covers a smaller inner-urban area ranging outwards to between 12 km to 20 km (or 8 to 14 miles), has a higher train frequency and runs on separate tracks (underground or elevated), whereas commuter rail often shares tracks, technology and the legal framework within mainline railway systems.
However, the classification as a metro or rapid rail can be difficult as both may typically cover a metropolitan area exclusively, run on separate tracks in the centre, and often feature purpose-built rolling stock. The fact that the terminology is not standardised across countries (even across English-speaking countries) further complicates matters. This distinction is most easily made when there are two (or more) systems such as New York's subway and the LIRR, Metro-North along with PATH, Paris' Métro and RER along with Transilien, London's tube lines of the Underground and the Overground, (future) Crossrail, Thameslink along with other commuter rail operators, Madrid's Metro and Cercanías, Barcelona's Metro and Rodalies, and Tokyo's subway and the JR lines along with various privately owned and operated commuter rail systems.
In Germany the S-Bahn is considered as a train category of its own, and exists in many of the large cities and in some other areas. They can be divided into two major types. In Berlin and Hamburg the S-Bahn systems do fulfill all considerations of a true metro system (despite the existence of U-Bahns as well). The trains run on tracks that are entirely separated from other trains, they have most of their stations within highly populated urban areas, has short distances between stations, has high frequency departures (all day) at fixed minutes and uses tunnels. The main difference between the S-Bahn systems of Berlin and Hamburg compared to the U-Bahns of the same cities are most notable at major railroad stations, where their (track-separated) platforms are located parallel to common railroad platforms. Some S-Bahn lines do run a bit further out from the city centre, compared with U-Bahn. This type of S-train also exists in Copenhagen (where a metro system also exists) and in Vienna (where the S-Bahn and U-Bahn constitute a common system). In Hamburg and Copenhagen, other, diesel driven trains, do continue where the S-Bahn ends ("A-Bahn" in Hamburg area, and "L-tog" in Copenhagen). In both Berlin and Copenhagen a ring line (circle line) is run by S-trains through highly populated boroughs, but outside the city centre core. (In Copenhagen the circle isn't complete, due to the city's location by the sea)
The second type, found in the Ruhr area, has longer lines and lacks a separate track system, and the trains runs between cities rather than within a city, although cities like Dortmund, Essen, Gelsenkirchen and Düsseldorf are almost agglomerated together. This type of S-Bahn also applies to Munich and Frankfurt. S-Bahns does also exist in some mid-size cities like Rostock and Magdeburg, but in that case the S-trains do not depart as often as metro systems do, the tracks are not separated from other trains and the number of lines are few. The distances between stations however are usually short.
S-trains (S-Bahns) are a rather wide concept but only in a number of cases can they be truly considered as commuter rail. The consideration for this is open to subjective thoughts and different opinions however, especially since such S-trains only exists in a few countries (Germany, Austria, Denmark, Italy and Romania) and do differ from city to city even within these countries.
Regional rail usually provides rail services between towns and cities, rather than purely linking major population hubs in the way inter-city rail does. Regional rail operates outside major cities. Unlike Inter-city, it stops at most or all stations between cities. It provides a service between smaller communities along the line, and also connections with long-distance services at interchange stations located at junctions or at larger towns along the line. Alternative names are "local train" or "stopping train". Examples include the former BR's Regional Railways, France's TER (Transport express régional), Germany's DB Regio and South Korea's Tonggeun services. Regional rail does not exist in this sense in the United States, so the term "regional rail" has become synonymous with commuter rail there, although the two are more clearly defined in Europe.
In some European countries the distinction between commuter trains and long-distance/intercity trains is very hard to make, because of the relatively short distances involved. For example, so-called "intercity" trains in Belgium and the Netherlands carry many commuters and their equipment, range and speeds are similar to those of commuter trains in some larger countries.
Russian commuter trains, on the other hand, frequently cover areas larger than Belgium itself, although these are still short distances by Russian standards. They have a different ticketing system from long-distance trains, and in major cities they often operate from a separate section of the train station.
The easiest way to identify these "inter-city" services is that they tend to operate as express services - only linking the main stations in the cities they link, not stopping at any other stations. However, this term is used in Australia (Sydney for example) to describe the regional trains operating beyond the boundaries of the suburban services, even though some of these "inter-city" services stop all stations similar to German regional services. In this regard, the German service delineations and corresponding naming conventions are clearer and better used for academic purposes.
Sometimes high-speed rail can serve daily use of commuters. The Japanese Shinkansen high speed rail system is heavily used by commuters in the Greater Tokyo Area. They commute between 100 and 200 km by Shinkansen. To meet the demand of commuters, JR sells commuter discount passes and operates 16-car bilevel E4 Series Shinkansen trains at rush hour, providing a capacity of 1,600 seats. Several lines in China such as the Beijing–Tianjin Intercity Railway, and the Shanghai–Nanjing High-Speed Railway, serve a similar role with many more under construction or planned. The high-speed services linking Zurich, Bern and Basel in Switzerland have brought the Central Business Districts (CBDs) of these three cities within 1 hour of each other. This has resulted in unexpectedly high demand for new commuter trips between the three cities and a corresponding increase in suburban rail passengers accessing the high-speed services at the main city-centre stations (or Hauptbahnhof).
Train types 
Commuter/suburban trains are usually optimized for maximum passenger volume, in most cases without sacrificing too much comfort and luggage space, though they seldom have all the amenities of long-distance trains. Cars may be single- or double-level, and aim to provide seating for all. Compared to intercity trains, they have less space, fewer amenities and limited baggage areas.
Multiple unit type 
Commuter rail trains are usually composed of multiple units, which are self-propelled, bidirectional, articulated passenger rail cars with driving motors on each (or every other) bogie. Depending on local circumstances and tradition they may be powered either by diesel engines located below the passenger compartment (diesel multiple units) or by electricity picked up from third rails or overhead lines (electric multiple units). Multiple units are almost invariably equipped with control cabs at both ends, which is why such units are so frequently used to provide commuter services, due to the associated short turn-around time.
Locomotive hauled services 
Locomotive hauled services are used in some countries or locations. This is often a case of asset sweating, by using a single large combined fleet for intercity and regional services. Loco hauled services are usually run in push-pull formation, that is, the train can run with the locomotive at the "front" or "rear" of the train (pushing or pulling). Trains are often equipped with a control cab at the other end of the train from the locomotive, allowing the train operator to operate the train from either end. The motive power for locomotive-hauled commuter trains may be either electric or Diesel-electric, although some countries, such as Germany and some of the former Soviet-bloc countries, also use diesel-hydraulic locomotives.
Seat plans 
In the USA and some other countries, a three-and-two seat plan is used. However, few people sit in the middle seat on these trains because they feel crowded and uncomfortable. It is said one industrial designer for one of New York City's commuter railroads, Metro-North, told people: "I designed the aisle seat with a half-back and no upholstery, so it will be very uncomfortable to sit there. They'll move in and take the center seat!" (This seating design can also be found on older New Jersey Transit and Long Island Rail Road rolling stock.)
In Japan, longitudinal (sideways window-lining) seating is widely used in many commuter rail trains to increase capacity in rush hours. Carriages are usually not organized to increase seating capacity (although in some trains at least one carriage would feature more doors to facilitate easier boarding and alighting and bench seats so that they can be folded up during rush hour to provide more standing room) even in the case of commuting longer than 50 km and commuters in the Greater Tokyo Area have to stand in the train for more than an hour.
Commuter rail systems in the world 
|This section requires expansion. (March 2009)|
Currently there are not many examples of commuter rail in Africa. Metrorail operates in the major cities of South Africa, and there are some commuter rail services in Algeria, Morocco, Alexandria, Egypt and Tunisia. In Algeria, SNTF operates commuter-rail lines between the capital Algiers and its southern and eastern suburbs. They also serve to connect Algiers' main universities to each other .
In Japan, commuter rail systems have extensive network and frequent service, and are heavily used. In many cases, Japanese commuter rail is operationally more like a typical metro system (with very high operating frequencies, an emphasis on standing passengers, short station spacing, and dedicated rights-of-way) than it is like commuter rail in other countries. Japanese commuter rail also tends to be heavily interlined with subway lines, with commuter rail trains continuing into the subway network, and then out onto different commuter rail systems on the other side of the city. Many Japanese commuter systems operate several levels of express trains to reduce the travel time to distant locations, often using station bypass tracks instead of dedicated express tracks. It is notable that the majority of Japanese commuter rail systems are owned and operated by private railway companies, without public subsidy.
In India, commuter rail systems are present in major cities. Mumbai Suburban Railway, the oldest suburban rail system in Asia, carries more than 7.24 million commuters on a daily basis which constitutes more than half of the total daily passenger capacity of the Indian Railways itself. Kolkata Suburban Railway is huge and extensive and covers large areas in Kolkata's hinterland. The Chennai Suburban Railway along with MRTS is another railway of comparison where almost 2 million people travel daily to different areas in Chennai. In Hyderabad, the MMTS mainly transports people from the city centre to HI-TEC city, the city's Information Technology hub. Other commuter railways in India include Delhi Suburban Railway, Pune Suburban Railway and Lucknow-Kanpur Suburban Railway.
Commuter trains are relatively uncommon in China, although small systems have been inaugurated in Beijing in 2008 and in Shanghai in 2012. Other systems have been built to high speed standards such as the Guangzhu MRT and Chengdu–Dujiangyan ICL. Commuter rail systems are also planned for Nanjing, Tianjin, and around the Pearl River Delta region.
In Iran, SYSTRA has done a "Tehran long term urban rail study". SYSTRA proposed 4 express lines which are similar to RER suburban lines in Paris. Tehran Metro is going to construct express lines. For instance, the Rahyab Behineh, a consultant for Tehran Metro, is studying Tehran Express Line 2. Tehran Metro currently has a commuter line between Tehran and Karaj.
Other examples in Asia include Seoul Metropolitan Subway of which some lines are suburban lines operated by Korail in South Korea, KTM Komuter in Malaysia, the Philippine National Railways orange line in Metro Manila, Philippines and KRL Jabotabek in Jakarta Metropolitan area, Indonesia.
Major metropolitan areas in most European countries are usually served by extensive commuter/suburban rail systems. Well-known examples include Beovoz in Belgrade, Serbia, S-Bahn in Germany, German-speaking areas of Switzerland and Austria, Proastiakos in Greece, RER in France, suburban lines in Milan (Italy), Cercanías in Spain, HÉV in Budapest, Hungary.
In Sweden, electrified commuter rail systems known as Pendeltåg are present in the cities of Stockholm and Gothenburg. The Stockholm commuter rail system, which began in 1968, is similar to the S-Bahn train systems of Munich and Frankfurt such that it may shares railway tracks with inter-city trains and freight trains, but for the most part run on its own dedicated tracks, and that it is mainly used to transport passengers from nearby towns and other suburban areas into the city centre, not for transportation inside the city centre. The Gothenburg commuter rail system, which began in 1960, is similar to the Stockholm system, but does fully share tracks with long-distance trains. Other train systems that are also considered as commuter rail but not counted as pendeltåg include Roslagsbanan and Saltsjöbanan in Stockholm, Upptåget in Uppsala County and Skåne Commuter Rail (Pågatågen) in Skåne County which also acts as a regional rail system, as it serves other cities over 100 km (62 miles) from the principal city of Malmö, and some trains may also cross the Øresund Bridge to reach the city of Copenhagen in Denmark.
North and Central America 
In the United States, Canada, Costa Rica, El Salvador and Mexico regional passenger rail services are provided by governmental or quasi-governmental agencies, with a limited number of metropolitan areas served.
South America 
Examples include an 899 km (559 mi) commuter system in the Buenos Aires metropolitan area, the 225 km (140 mi) long Supervia in Rio de Janeiro, and the Metrotrén in Santiago, Chile. Another example is Companhia Paulista de Trens Metropolitanos (CPTM) in Greater São Paulo, Brazil. CPTM has 93 stations with six lines, numbered starting on 7 (the lines 1 to 6 belong to the São Paulo Metro), with a total length of 260.8 kilometres (162.1 mi).
Major cities in Australia have suburban railway systems in their metropolitan areas. As with Japanese suburban railways or Germany's and Switzerland's S-Bahns, these Australian networks have far more frequent services and far higher ridership per capita than US 'commuter rail' in the usual sense of the term. To some US observers these networks may appear to operate as commuter/metro hybrids, however, they are simply the result of full utilisation of the available track capacity in the core of the suburban rail network, this being fed from multiple feeder lines. This is particularly so in Sydney and Melbourne, where headways on many lines in the core of the network reach 3–5 minutes in peaks and 10–20 minutes off peak (about 18 hours a day) and enter an underground loop for passenger distribution in the city centre; and where ridership per capita exceeds the sum of metro and commuter rail in comparable North American urban areas such as Toronto, Boston or the San Francisco Bay Area. All systems, however, are based on established main line rail systems, and track sharing with inter-city and freight services on parts of the network inhibit higher frequencies on some tracks. The main systems include:
- CityRail in Sydney, Newcastle and Wollongong. (largest metropolitan-wide network in Australia)
- Metro Trains Melbourne in Melbourne. ("Metro" in this case being an abbreviation of "metropolitan", to distinguish these services from regional trains under the V/Line brand.)
- QR Citytrain in Brisbane.
- Transperth Trains in Perth.
- TransAdelaide in Adelaide.
See also 
- List of suburban and commuter rail systems
- Public transport
- Cercanías, the commuter rail systems of Spain's major metropolitan areas
- Commuter rail in the United Kingdom
- Commuter rail in North America
- Commuter rail in Australia
- S-Bahn, the combined city center and suburban railway system metro in Austria, Germany, Switzerland and Denmark
- Commuter Rail & Transit News Current news concerning commuter rail development and issues