A SEPTA maintenance streetcar is followed by a passenger streetcar in west Philadelphia. Photo by Bill Mohnahan of Friends of the Philadelphia Trolleys.

It is one of the great ironies of American life that suburban sprawl—a low-density pattern of development that is difficult to serve with public transit—was created by public transit.  Frank J. Sprague created the first successful electric streetcar in Richmond, Virginia, in 1888.  Land developers rushed to build streetcar lines, loss leaders for the highly profitable residential development built along them.

In those days before cars became identified with automobiles, “streetcar” was two words; street cars were the same genus as rail cars, passenger cars, and box cars, but a species unique and easily identifiable.  A vehicle operating on the street, powered by electric wires could be only one thing.

Things have changed.  Today only the St. Charles Avenue Line in New Orleans (1835) and the Boston Mattapan Ashmont Line (1929) have remained in continuous operation since inception.  With a nationwide resurgence in interest in streetcars, several cities have restored historic lines on extant rails (Philadelphia’s Girard Street Line, San Francisco’s F Market Line) and many cities have created new streetcar systems, whether “heritage” lines as in Tampa and Little Rock that use reproduction cars, or modern, low floor systems as in Portland, Oregon and Tacoma, Washington.  Still another category is those systems using vintage cars on new tracks as in Memphis, Tennessee and Kenosha, Wisconsin.

After WWII as Americans lost interest in streetcars, Germany imported the idea as part of their rebuilding effort.  They took a venerable American institution and made the streetcar longer and stronger and put it in its own right-of-way (see Thompson’s story on the history of the streetcar). Stadtbahn was reimported to San Diego and then other U.S. cities as light rail (LRT), a very different mode from its long lost brother the streetcar.

This cable car in San Francisco differs from the historical understanding of the streetcar only in the propulsion system but it has its own designation in NTD. Photo by Scheib.

The federal government, through the National Transportation Database (NTD), makes no distinction between LRT and streetcar, merging the two into the light rail column.  A separate category may be in order.  After all, NTD still maintains a cable car category even though there is only a single city (San Francisco) operating one and a cable car is fundamentally different from a streetcar only in the propulsion system (an underground cable vs. an overhead wire).  Based on that standard Galveston’s diesel-powered trolleys have more in common with northeastern commuter rail than urban circulation, but Galveston is, for federal reporting purposes, light rail too.

There are some similarities; both LRT and streetcar operate on rails and mostly at-grade (i.e. on the same level as automobiles), and are usually powered by catenaries, but diverge rapidly from there.  LRT almost never operates in mixed traffic, which long ago defined streetcars, and LRT infrastructure is far heavier and more expensive to construct.  Compare two recently completed Seattle projects, the 1.3-mile South Lake Union Streetcar at $39 million per mile and the 14-mile light rail at $193 million per mile.

The TECO streetcar in Tampa has small stations and a dedicated right-of-way. It sounds like LRT but looks like streetcar. Photo by Scheib.

Streetcars, whether vintage, heritage, or modern, are always a single car, although modern streetcars are articulated (bend in sections) and thus are longer.  Where streetcar vehicles cannot have additional cars attached, LRT capacity is limited mostly by the length of the platforms available to the service provider.

In their behavior, the streetcar, at least in theory, acts more like a city bus than LRT, with stops from a quarter- to a half-mile apart.  Modern cars need only a platform at the same level as the floor for ADA compliant stops whereas heritage cars typically have “stations” with a ramp for loading of wheelchairs.  Absent the station platforms, a lift must be installed on the vehicle.  Philadelphia, for example, uses its pre-ADA islands and has lifts on the 1930s Presidents’ Conference Committee (PCC) streetcars.

New Jersey Transit's gleaming white cars of the Hudson Bergen Line mix beautifully with the urban environment around them, but the multiple cars put them in the LRT category. Photo by Scheib.

LRT vehicles are regional in nature and as such are capable of higher speeds than streetcars; compare a Siemens S70 LRT vehicle with a top speed of 66 mph to the Skoda streetcar (used in Portland), which has a top speed of 42 mph.  In a tight urban environment, a streetcar is unlikely ever to achieve that top speed, but it is easy to see how an agency building a new system may want to take advantage of that speed, spacing the stops a bit and acting a little like light rail on the cheap.

Terminology matters, too.  Boston’s Mattapan Ashmont (M-line) is billed as a High Speed Line, a vestigial use of a term normally reserved for heavy rail (subways).  It is part of the heavy rail Red Line but runs on PCC cars.  Philly’s subway-surface lines operate in mixed traffic for most of their routes and the vehicle is a single, electrically-powered rail car.  In the city center the SS lines are accessed underground in subways, which is contrary to the spirit of the eponymous streetcar.  Likewise, Tampa’s TECO line uses reproduction cars that most closely fit the historical idea of streetcar, and they run on catenary wires, but have a dedicated right-of-way and are not in the street, strictly speaking.

Confounding the definition of streetcar, “trolley”  is an historical name for streetcars that is easily confused with other vehicles.  Many systems use buses designed to look like vintage streetcars and call them trolleys.  Trackless trolleys (or trolley buses) are buses powered by catenaries, but look nothing like a streetcar.  The San Diego Metropolitan Transit System calls its light rail system—wait for it—the San Diego Trolley.  Thirty years ago SEPTA ordered a group of cars from Kawasaki Railcars for use in its subway-surface lines.  The cars are boxy and contemporary, a single car in length, powered by overhead wires, and often used in mixed-traffic.  They sound like streetcars but are called light rail vehicles, LRVs.  We called Ken Takeda at Kawasaki to ask why:  “In the request for proposals, SEPTA asked for an LRV.”

Old Town Trolleys are buses, despite using an old name for streetcars.

Having been largely obliterated as a means of mass transportation after WWII, streetcars as they have been reconstituted are nowhere and never the one thing they were between 1890 and 1920: the dominant form of mechanized urban transport.  What they are exactly is hard to accurately define.  At the end of the day, precision is elusive.  If asked to identify one, the best we can do is to resort to Justice Potter Stewart’s Pornography Axiom and say, “I know it when I see it.”

This article first appeared in the Streetcar issue of Trip Planner Magazine.