Aliases: Metropolitan Rail (MR), Regional Rail (RGR)
Confusion: "Commuter" (originally from the American railroad usage "to commute" (reduce) the price of a ticket for urban/suburban travellers) has come to mean anyone travelling between home and work, or between home and day business in an urban area.
Description: This is the technology that most resembles intercity railroading. Train frequencies are the least, typically mid-day headways are half-hourly or more. Suburban stations are typically spaced more than a kilometre or two apart. The tracks may be shared with freight services, street-running is rare, diesel locomotive-hauled trains are common, along with electric locomotive- hauled trains and multiple-unit trainsets. Service is typically city-centre to outlying suburbs.
North American Examples: AMT (Montreal QC), Coaster (San Diego CA), GO Trains (Toronto ON), Long Island Rail Road (New York City NY), MARC (Washington DC-MD-WV, Baltimore MD), MBTA (Boston MA-RI), Metro Link (Los Angeles CA), Metro North (New York City NY-CT), Metra (Chicago IL-WS), New Jersey Transit "rail lines" (Atlantic City NJ-PA, New York City NY-NJ), Penninsula Commute (San Francisco CA, San Jose CA), Shore Line East RR (New Haven CT), SEPTA "regional rail lines" (Philadelphia PA-NJ-DE), Trinity Express (Dallas TX), TriRail (Miami FL), Virginia Railway Express (Washington DC-VA), West Coast Express (Vancouver BC).
Aliases: Subway, Rapid Transit, Metro
Confusion: Using "Heavy Rail" to describe intercity railroads.
Description: Typified by multiple-car trains with high capacity operating at close frequencies (as little as a 60 seconds in peak hours). Electric powered multiple-unit trains are nearly universal. Car-floor level loading platforms are nearly universal, as are exclusive rights-of-way (even level crossings with vehicle traffic are rare). Service is typically intra-urban, with stations spaced from a few city blocks to around a kilometre or two apart.
North American Examples: Atlanta GA, Baltimore MD "Metro," Boston MA "Red, Blue and Orange lines," Chicago IL, Los Angeles CA "Red line," Mexico City DF "Metro," Miami FL "MetroRail," Montreal QC "Metro," New York City NY "IRT, IND-BMT and SIRT lines," New York City NY-NJ "PATH," Philadelphia PA "Market-Frankfort, Broad lines," Philadelphia PA-NJ "PATCO," Toronto ON "Yonge-University-Spadina, Bloor-Danforth" Washington DC-VA-MD.
Notes: The Vancouver SkyTrain and Toronto Scarborough RT lines represent the bottom end of HR characteristics, coming the closest to LR. The Skokie Swift (Chicago) and the Cleveland Red line are also LR-ish HR lines. BART in San Francisco comes the closest to being CR rather than HR, because of its station spacing and regional service area.
Description: Essentially a transit technology applied in the moving of people in or around small concentrated service areas, such as downtowns, airports, amusement parks, zoos, and educational campuses. Some writers attempt to divide out intra-complex systems from inter-complex systems, describing only the latter as public transit. Configuration is usually small vehicles operating frequently, with stations spaced close together. Technology varies greatly, including monorails, rubber tired tracked vehicles, etc....
North American Examples: Detroit MI (DPM), Jacksonville FL, Miami FL (MetroMover), Morgantown WV (University of West Virginia), New York City (Roosevelt Island aerial tramway), Seattle WA (Seattle Center Monorail), Tampa FL.
Notes: The Downtown People Mover in Detroit uses the same technology as SkyTrain in Vancouver and the Scarborough RT in Toronto. The above list is derived from The New Electric Railway Journal whose editor does not list intra-complex people movers as public transit.
Aliases: Incline Railways. Incline Planes.
Description: Site-specific implementation of rail transit to scaling steep hills. Often cable-hauled, with unpowered cars moved by a stationary engine. More of an outdoors elevator than anything else. [I call them an old variation on the people mover idea].
North American Examples: Chattanooga TN (Lookout Mountain Incline), Dubuque IA, Johnstown PA, Niagara Falls ON (Falls Incline), Pittsburgh PA (Monongahela and Dunseque Inclines), Quebec City QC.
Aliases: Streetcars (SCR), trolleys, trolley cars, surface cars, cars, trams, pre-metro.
Confusion: British term "light railway" meaning "like a tramway but without street running". Others see LR as too broad, and divide it into two categories, one with a rapid transit connotation and the other more a street railway.
Description: Catch-all category for rail transit systems that don't fit the other descriptions. Typically electric powered single cars, short MU trains or car-and-trailer combinations. Stop spacing closest to bus pattern. Right-of-way options include everything from subway to street running in mixed traffic (sometimes all on the same line!). Overhead power delivery most common (but not universal). Curb-height platforms, floor-height platforms or both.
North American Examples: Baltimore MD (Central Light Rail), Boston MA (Green line, Ashmont-Mattapan red line), Calgary AB (C-Train), Cleveland OH (Shaker Heights (Green, Blue) lines), Dallas TX Denver CO, Edmonton AB, Fort Worth TX (Tandy subway), Guadalajara JA, Los Angeles CA (Blue and Green Lines), Mexico City DF (STE: Xochimilco line), Monterrey NL (Metrorrey), New Orleans LA (St. Charles line), Newark NJ (7 City Subway), Philadelphia (subway-surface (green) lines, Norristown, Media-Sharon Hill), Pittsburgh PA, Portland OR (MAX), Sacramento CA, Saint Louis MO-IL (MetroLink), San Diego CA, San Francisco CA (Muni Metro J, K, L, M, N and Cable cars C, PH, PM), San Jose CA, Toronto ON (surface car lines and Spadina Line).
Notes: The Buffalo and Edmonton LR lines most resemble HR in their right-of-way configuration. The Norristown line in Philadelphia is kind of a cross between HR track and performance, LR capacity and CR service area. The Media-Sharon Hill lines in Philadelphia are light rail in most characteristics but serve a CR-like area. New Orleans, and the cable cars in San Francisco, would be called Heritage Trolleys anywhere except that they are "original technology" where they are now.
Aliases: Antique trolley, Historic trolley, Heritage tramway.
Description: A fairly recent phenomenon. Antique streetcars, or reasonable facsimilies, operating on new or restored track in the urban environment. Often aimed at tourists but performing a local transportation role as well. Excludes museums, and circuits where point-to-point rides are impossible.
North American Examples: Calgary AB (Heritage Park), Chattanooga TN (Chattanooga Choo Choo Complex), Chisholm MN (Ironworld), Clear Lake IA (Iowa Trolley Park), Dallas TX (McKinney Avenue Transit Authority), Denver CO (Denver Rail Heritage Society), Detroit MI (Detroit Citizens Railway), Duluth MN (Duluth Depot Museum), Edmonton AB (Old Strathcona), Fort Collins CO, Fort Smith AR, French Lick IN (Springs Valley Electric Railway), Galveston TX, Lake Buena Vista (Orlando) FL (Grand Cypress Resort line), Lowell MA, Memphis TN, Minneapolis MN (Como-Lake Harriet line), Nelson BC, New Orleans LA (Riverfront line), Philadelphia PA (Penn's Landing Trolley, Germantown trolley), Portland OR (Oswego Trolley, trolleys on downtown MAX track), Rockford IL, San Francisco CA (F - under construction), San Jose CA (Historic Trolleys on downtown LR tracks), Seattle WA (Waterfront Streetcar), Tucson AZ (Old Pueblo Trolley), Whitehorse YT, Yakima WA (Yakima Interurban Lines Assoc.).
Aliases: Trolleys, Trackless Trolleys, Trolleybuses, Trolley Coaches, Curbliners.
Confusion: Those little buses dolled up to look like old-time streetcars and marketed by manufacturers as "trolleys" or "trolleybuses."
Description: Electric powered buses operating from overhead power, able to operate in mixed traffic. Some systems have dual power sources and can operate from a few metres to many kilometres away from overhead.
North American Examples: Boston MA, Dayton OH, Edmonton AB, Guadalajara JA, Mexico City DF, Philadelphia PA, San Francisco CA, Seattle WA, Vancouver BC.