Comparison of 'Rail' transit modes
HOW DOES COMMUTER RAIL DIFFER FROM LIGHT RAIL AND HEAVY RAIL?
Commuter rail is not the same as light rail or heavy rail. Commuter rail is one of several types, or "modes," of rail passenger service used for urban public transit. It has been the subject of increasing interest within the United States in recent years, chiefly because it offers the potential for providing attractive, high-quality rapid transit service at a more reasonable cost when compared with other types of urban rail systems, such as light rail or heavy rail
In spite of the current widespread interest in commuter rail—especially in areas of the United States where commuter rail service does not currently exist—there is frequently confusion as to what commuter rail is, what passenger markets it is intended to serve, and the important characteristics that distinguish commuter rail from other types of rail transit. While different types of bus service are commonplace and familiar to most people throughout the United States, it is important and useful to define the term "commuter rail" and to describe how commuter rail service differs from other typesofrailwaypassengertransportationservices.Acomparisonofsomeofthebasiccharacteristics attendant to each of these types of rail passenger services is provided in the accompanying table.
Commuter Rail
Commuter rail may be defined as a type of passenger train transit service that utilizes diesel-electric or electrically propelled trains, operating over existing railway trackage on the same rights-of-way used by intercity railway freight and passenger trains. Common practice in the United States and Canada is to use trains of coaches drawn by diesel-electric locomotives, as opposed to electrified multiple-unit equipment. Some commuter rail service is provided by self-propelled diesel-powered coaches. Fare collection is typically on board the train by cash or ticket, and boarding is normally from low platforms.
Commuter rail normally accommodates mainly the longest-distance trips made within metropolitan regions during weekday peak travel periods at high overall average operating speeds of typically between 30 and 50 miles per hour, with relatively few station stops. Typical commuter rail routes range from 20 to 50 miles in length. Because the railway track usually is shared with intercity freight and passenger trains, commuter rail normally requires neither the acquisition of new right-of-way nor the construction of new main-line trackage. However, for safety and operational reasons, locomotives and cars must be manufactured to main-line railway standards with respect to size and strength. These characteristics, together with the relatively long station spacings of two to five mites, characterize commuter rail as having the ability to provide a very high level of riding comfort for passengers.
Commuter rail is the oldest of all railway passenger transit modes, but presently exists only in corridors with substantial concentrations of passenger-trip origins in the outlying suburban areas of a corridor with destinations in the central business district of the corridor. The closest operating commuter rail system to Southeastern Wisconsin is the system centered on the central business district of the City of Chicago and operated by Metra. Metra is the Commuter Rail Division of the Regional Transportation Authority of Northeastern Illinois. The Metra system is one of the largest commuter rail systems in North America, and is generally regarded as among the best managed and most cost-effective. Metra, as well as some other existing commuter rail systems in the United
States and Canada, has made efforts to attract off-peak as well as peak-travel-period ridership and markets its serviceto attract passengers usingthe private automobiletothe railwayservice. Extensive park-ride facilities are usually associated with commuter rail services. Some existing systems, including Metra, have begun to give consideration to finding ways of serving non-central-businessdistrict-oriented trips in metropolitan areas. Typical commuter rail frequency of service on individual routes may be every 30 minutes in the peak travel direction during weekday peak travel periods, with midday, evening, and weekend service frequencies varying from one to three hours where such nonpeak service is operated at all.
In the United States and Canada, commuter rail systems are found only in the largest metropolitan areas. Large-scale commuter rail operations, which include frequent peak-period service and a base service during nonpeak periods and weekends, are found in the Boston, Chicago, Montreal, New York, Philadelphia, San Francisco, and Toronto areas. Other commuter rail operations with service provided principally during weekday peak periods operate in the Baltimore and Washington, D.C., areas. New commuter rail operations which include peak-period service and some limited nonpeak weekday service have commenced operations within the last 10 years in the Dallas, Los Angeles, Miami, New Haven, and San Diego areas. Specialized commuter rail services that function more as local-area shuttles have also commenced operations in the southern New Jersey and Syracuse areas. The potential for commuter rail services continues to be considered in a number of other metropolitan areas, including the Atlanta, Cleveland, New Orleans, Oakland, St. Louis, Seattle, and Tampa areas. In other countries, commuter rail is often referred to as "regional rail to emphasize the length of the lines involved and to emphasize the high level of service provided throughout the entire day, as opposed to the mainly peak-travel-period, peak-direction service typicaily provided by existing commuter rail systems in the United States.
Light Rail
Light rail may be defined as a type of urban passenger transportation service that utilizes electrically propelled cars, or trains of cars, operating primarily at surface level either over exclusive rights-ofway or over public streets. Light rail is essentially an improved and modernized version of the old streetcars and electric interurban railways that were common in the United States from the 1890s through World War II. Light rail can best be envisioned as trains of one to three articulated rail vehicles powered by electricity from overhead trolley wires. Fare collection is typically selfservice, using tickets purchased from vending machines. Boarding may be from either high- or lowlevel platforms.
The trackage used for light rail operations is not normally shared with freight and other railway passenger trains. Light rail systems are intended to accommodate all types and lengths of passenger trips within the most densely developed portions of metropolitan areas during weekday peak travel periods, as well as during midday and evening off-peak travel periods and on weekends. Typically, light rail routes range from five to 15 miles in length. Normal station spacing for such systems ranges from one-quarter mile to one mile, thus providing good access while maintaining reasonable overall operating speeds. Typical average overall speeds for express transit light rail routes operating primarily over public streets may range from 10 to 20 miles per hour. Such speeds for rapid light rail routes operating extensively over exclusive, grade-separated rights-of-way may range from 20 to 30 miles per hour. Frequency of service on light rail systems typically ranges from five to 10 minutes during peak travel periods, and from 10 to 20 minutes during other times of the day. Extensive park-ride facilities may be provided at outlying stations, but substantial numbers of riders access light rail facilities by walking to stations or using feeder bus service. Unlike commuter rail, which utilizes existing railway trackage, the development of a new light rail system typically requires the acquisition or dedication of new rights-of-way and the construction of new trackage. Thus, the capital cost of implementing a light rail route will normally be significantly greater than the capital cost of a commuter rail route.
Within the United States and Canada, examples of light rail systems include the San Diego Trolley, MetroLink in St. Louis, C-Train in Calgary, Metropolitan Area Express (MAX) in Portland, and the Sacramento Regional Transit District system.
Heavy Rail
Heavyrail may be defined as a type of urban passengertransportation servicethat utilizes electrically propelled trains of cars operating over fully grade-separated rights-of-way. Heavy rail may best be envisioned as high-capacity, semiautomated trains of four to 10 cars powered by electricity from a third rail. Because heavy rail systems require an exclusive, completely grade-separated alignment, extensive subways and elevated structures are needed, both of which are costly and disruptive to construct. Fare collection is typically done at stations, and boarding is from highlevel platforms.
The trackage used for heavy rail operations is not shared with freight and other railway passenger trains. Like light rail, heavy rail systems are intended to accommodate all types and iengths of passenger trips within the most densely developed portions of metropolitan areas during weekday peak travel periods, as well as during midday and evening off-peak travel periods and on weekends. Typically, heavy rail routes range from five to 15 miles in length. Normai station spacing for such systems ranges from one-half mile to two miles. Typical average overall speeds may range from 25 to 40 miles per hour. Frequency of service on heavy rail systems typically ranges from five to 10 minutes during peak travel periods, and from 10 to 20 minutes during other times of the day. Extensive park-ride facilities may be provided at outlying stations, but substantial numbers of riders access heavy rail facilities by walking to stations or using feeder bus service. Unlike commuter rail, which utilizes existing railway trackage already in place, the development of a heavy rail system typically requires the acquisition or dedication of new rights-of-way and the construction of new trackage. Unlike ilght rail, which is intended to operate primarily at surface level, heavy rail requires fully grade-separated elevated or subway locations. Thus, the capital cost of implementing a heavy rail route will normally be much greater than the capital cost of either a commuter rail or light rail route.
Within the United States and Canada, examples of heavy rail systems include the Chicago Transit Authority, or "El," the New York City subway system, Metro in Washington, D.C., MARTA in Atlanta, the Red Line in Los Angeles, and BART in San Francisco and Oakland.
High-Speed Rail
"High-speed rail " is a technical term which defines a type of long-distance intercity railway passenger train service. While this type of service has also been a subject of increasing interest within the United States, it is intended to serve the same passenger market as does Amtrak, that is, passengers traveling between metropolitan areas, rather than passengers traveling within metropolitan areas, the passenger market of commuter rail, light rail, and heavy rail.
High-speed rail would require the use of either an improved existing railway alignment or a new alignment that includes very gentle horizontal and vertical curvatures as well as few, if any, grade crossings. While commuter rail, light rail, and heavy rail trains may be expected to have maximum operating speeds of between 50 and 79 miles per hour, high-speed intercitytrains may be envisioned as operating at maximum speeds of anywhere from 125 to 250 miles per hour. Conventional Amtrak trains typically operate at top speeds of 79 to 90 miles per hour. For example, the present maximum operating speed for the Amtrak trains operating between Milwaukee and Chicago is 79 miles per hour. The only true high-speed intercity rail service currently operating in North America is in the corridor between New York and Washington, D.C., although high-speed rail systems are common in other parts of the world, especially France, Germany, the United Kingdom, and Japan.
[Editorial note, Dec. 2002: NorthEast Corridor speeds remain a matter of controversy in the interval since 150 mph Acela Express trains began operation in 2000 on portions of track between Boston and New York City. Much of the Boston-NYC-Philadelphia-Washington DC track is overdue for major maintenance, thus HSR as defined above is only partially operational.]
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