I’ve noticed some confusion on Columbus Underground and other web forums about the differences between streetcars and light rail, light rail and heavy rail, and heavy rail and commuter rail. In an effort to get more of us on the same track, I have summarized some common characteristics of each rail mode and provided some domestic examples.
If you disagree with any of my definitions or examples, please comment. I don’t know everything about rail, but as a transportation professional, I feel I can usually classify an urban public transit system when I see it. So if you choose to comment, I’ll either update my list…or disagree with you in the comment section 😛
Heavy Rail – The term “heavy rail” refers to both the passenger capacity and the weight of the vehicles. According to the American Public Transportation Association (APTA), heavy rail is “a mode of transit service operating on 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.”
Heavy rail does not typically include inter-city trains or freight trains.
Other Names – Metro, Subway, Rapid Transit
Right-of-Way – Grade-separated from mixed traffic
Power – Typically electrified third rail
Rolling Stock (vehicles) – Multi-car trains
Schedules – Frequent service most of the day every day, possibly with breaks overnight
Cost – Very expensive due to the required tunnels for a subway or structures to elevate the line
US Examples – New York City Subway, PATH, Los Angeles Red Line, Chicago Transit Authority “El”, SEPTA Broad and Market Street Lines, Miami-Dade Metrorail, WMATA Metro, Atlanta MARTA, Boston “T” (Red, Orange, and Blue lines), BART, Baltimore MTA, Cleveland Rapid (Red line)
Commuter Rail – The APTA says commuter rail is “characterized by 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. Most service is provided on routes of current or former freight railroads.”
A commuter rail line can be very long; the line I ride every day runs over 50 miles from Chicago to Kenosha, WI. Stations can be spaced relatively infrequently to maintain good travel times. The destination city is usually served by a single central station, like Penn Station or Grand Central Station in New York.
Other Names – Regional rail, Suburban rail
Right-of-Way – Freight rail tracks, usually with at least some at-grade gated crossings
Power – Typically Diesel Powered, although some are electrified with overhead wires
Rolling Stock (vehicles) – Multi-car trains, sometimes double-decker
Schedules – Frequent during peak hours with express options, but can be infrequent during the middle of the day, at night, or on weekends. Coordinating with freight service may be difficult or undesirable, especially for the freight railroad.
Cost – Because right-of-way is typically shared with a freight railroad, commuter rail can be relatively affordable.
US Examples – NYC Long Island Railroad, NYC Metro North Commuter Railroad, New Jersey Transit (NJT), LA Metrolink, Chicago Metra, NICTD South Shore Line (arguably “interurban railroad), Dallas-Fort Worth Trinity Railway Express, Philly SEPTA Regional Rail Lines, Miami Tri-Rail, Virginia Railway Express (VRE), MARC, Boston MBTA Commuter Rail, SF Caltrain, San Jose Altamont Commuter Express (ACE), Seattle Sounder, Minneapolis Northstar Commuter Rail (under construction), San Diego Coaster, Tri-Met Washington County Commuter Rail (under construction), Nashville Music City Star, Salt Lake City UTA Frontrunner, New Haven Shore Line East, Albuquerque Rail Runner Express
Light Rail – Light rail carries lighter passenger volumes than heavy rail due to having fewer cars in a train. Short trains are necessary because part of a light rail line is often at grade on city streets and the train cannot be longer than a city block or it would block traffic. The APTA defines light rail as “a mode of transit service operating passenger rail cars singly (or in short, usually two-car or three-car, trains) on fixed rails in right-of-way that is often separated from other traffic for part or 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; driven by an operator on board the vehicle; and may have either high platform loading or low level boarding using steps.”
Other Names – Tram (UK)
Right-of-Way – Typically at-grade for at least a small portion of line, but modern systems are not likely to share a lane with mixed traffic
Power – Typically Overhead Electric Catenary Wire
Rolling Stock (vehicles) – Two or Three-Car Trains
Schedules – Frequent service during most of the day every day, but less frequent than heavy rail due to lower ridership demand.
Cost – Varies considerably depending on right-of-way used, but cheaper than heavy rail due to fewer grade separations and more expensive than commuter rail due to independent right-of-way, electrification, and more stations per mile.
US Examples – NJT Newark Subway, Hudson-Bergen, and River lines, LA Metro Green, Blue, and Gold lines, Dallas DART, SEPTA Trolleys, Houston Metrorail, Boston MBTA Green Line, SF MUNI Lines and Third Street Light Rail, Phoenix Valley Metro Light Rail, Seattle Sound Transit Link (under construction), Minneapolis Hiawatha Line, San Diego MTS Trolley, St. Louis Metrolink, Baltimore MTA, Denver RTD, Pittsburgh “T”, Portland MAX, Cleveland Rapid (Blue and Green lines), Sacramento RTD, Santa Clara VTA, Charlotte LYNX, Buffalo NFTA Metro Rail, Salt Lake City UTA
Streetcar – A streetcar is essentially light rail, but with only one car instead of multiple-car trains. Streetcars tend to operate in mixed traffic, stop more often than light rail trains, and mostly serve as a circulator service in a high-demand area, rather than a commuting service for longer distances as they once did.
Other Names – Trolley (especially if historic), Tram
Right-of-Way – Typically on-street mixed traffic, but some lines have own right-of-way or are in medians of boulevards
Power – Typically Overhead Electric Catenary Wire or Trolley Wire.
Rolling Stock (vehicles) – Single cars. Modern streetcars are usually articulated (accordion-style).
Schedules – Frequent service most of the day, every day, with breaks overnight
Cost – Streetcar rails may require less depth of excavation than light rail tracks, and therefore are less costly and quicker to construct. They rarely require their own right-of-way.
US Modern Streetcar Examples – Seattle South Lake Union Streetcar, Portland Streetcar, Tacoma Link
US Historic or Replica Streetcar Examples – Dallas McKinney Avenue Streetcar, Galveston Island Trolley, San Francisco F Line, Tampa TECO Line, Charlotte Trolley, Memphis Trolley, New Orleans Streetcars, Tucson Old Pueblo Trolley, Little Rock River Rail, Fort Collins Municipal Railway, Kenosha Streetcar