# Light rail in the United States

Light rail is a mode of rail-based transport, usually urban in nature.
Light-rail systems are typically designed to carry fewer passengers than heavy-rail systems like commuter rail or rapid transit (subway). They can operate in mixed traffic (street running) or on routes that are not entirely grade-separated.
They typically take one of four forms: "first-generation" legacy systems, "second-generation" modern light-rail systems, streetcars, and hybrid rail systems (light rail with some commuter-rail features). All use similar technologies, and some systems blur the lines between the different forms.
The United States has 27 light-rail systems, as counted by the Light Rail Transit Association, not including streetcar systems. Six of them (Boston, Los Angeles, Philadelphia, Portland (Oregon), San Diego, and San Francisco) achieve more than 30 million unlinked passenger transits per year. The next-most are in Germany, 10; and Japan, nine.

## History

From the mid-19th century onwards, horse-drawn trams (or horsecars) were used in cities around the world. The St. Charles Avenue Line of New Orleans' streetcar system is the oldest continuously operating street railway system in the world, beginning operation as a horse-drawn system in 1835.
In the late 1880s, electrically powered street railways became technically feasible with the invention of a trolley pole system of collecting current. American inventor Frank J. Sprague installed the first successful electrified trolley system in Richmond, Virginia, in 1888. Before the invention of the internal combustion engine and the advent of motor-buses, they were the only practical means of public transport around cities.
The streetcar systems constructed in the 19th and early 20th centuries typically ran single-car setups. Some rail lines experimented with multiple-unit configurations, joining streetcars to make short trains, but this did not become common until later. When lines were built over longer distances (typically with a single track) before good roads were common, they were generally called interurban streetcars or radial railways in North America.
Historically, the rail gauge has had considerable variations, with a variety of gauges common in many early systems (e.g. the broad Pennsylvania trolley gauge, etc. used by New Orleans' streetcars and by the light rail systems in Philadelphia and Pittsburgh). However, most modern second-generation light rail systems now operate on standard gauge rail.
After World War II, six major cities in the United States (Boston, Newark, New Orleans, Philadelphia, Pittsburgh, San Francisco) continued to operate large first-generation streetcar systems, although most of them were later converted to modern light rail standards. Toronto in Canada marks the other city in North America with a continuing first-generation streetcar system. Additionally, a seventh American city, Cleveland, maintained an interurban system (e.g. the Blue and Green Lines) equivalent to what is now "light rail", that opened before World War I, and which is still in operation to this day.
When several of these cities upgraded to new technology (e.g. San Francisco, Newark, and Pittsburgh), they called it "light rail" to differentiate it from their existing streetcar systems since some continued to operate portions of both the old and new systems.
In the United States, most of the original first-generation streetcar systems were decommissioned from the 1950s onward through approximately 1970 as the usage of the automobile increased through government policy.
Although a few traditional streetcar or trolley systems still exist to this day the term "light rail" has come to mean a different type of rail system. Modern light rail technology has primarily German origins, since an attempt by Boeing Vertol to introduce a new American light rail vehicle was a technical failure. After World War II, the Germans retained their streetcar (Straßenbahn) networks and evolved them into model light rail systems (Stadtbahn).
The renaissance of light rail in the United States began in 1981, when the first truly second-generation light rail system was inaugurated in the United States, the San Diego Trolley in California, which adopted use of the German Siemens-Duewag U2 light rail vehicle. (This was just three years after the first North American second-generation light rail system opened in the Canadian city of Edmonton, Alberta in 1978, and which used the same German Siemens-Duewag U2 vehicles as San Diego). Other North American cities, particularly on the West Coast, began planning their own light rail systems in the 1980s.
As of March 2020, there are a total of 53 operational light rail-type lines and systems (noting that some cities, such as Philadelphia, Portland, San Francisco and Seattle, have more than one light rail system) that offer regular year-round transit service in the United States: 26 modern light rail systems, 14 modern streetcar systems, and 13 heritage streetcar systems (including the San Francisco cable car system).

## "First-generation" legacy systems

First-generation systems are typically vestigial elements of sprawling streetcar systems decommissioned between the 1950s and about 1970. These elements were generally preserved because of their high ridership and some exclusive right of way. Many have been at least partly upgraded to more closely resemble the more modern second-generation light rail systems.
| Location | Operator | System | Year originally opened | System length | Lines | Current type | Description |
| Boston | MBTA | MBTA Green Line | 1897 | 26.7 mi (43.0 km) | 4 | Light rail | While changes were made to the original 1897 Tremont Street subway in 1962 and 2004, and to some of the line routes over the years, and the Green Line's streetcar A branch was closed in 1969, both systems have run intact with mostly uninterrupted service since their opening dates. |
| Boston | MBTA | Mattapan Line | 1929 | 2.5 mi (4.0 km) | 1 | Light rail | While changes were made to the original 1897 Tremont Street subway in 1962 and 2004, and to some of the line routes over the years, and the Green Line's streetcar A branch was closed in 1969, both systems have run intact with mostly uninterrupted service since their opening dates. |
| Cleveland | Greater Cleveland RTA | Green Line / Blue Line | 1913 | 15.3 mi (24.6 km) | 2 | Light rail | Aside from line and station renovations in the early 1980s, and the Waterfront extension in 1996, these lines have operated essentially uninterrupted as light rail (interurbans) from their opening. |
| Newark | New Jersey Transit | Newark Light Rail | 1935 | 6.2 mi (10.0 km) | 2 | Light rail | Outside of a switch to modern vehicles in 2001 and extensions in 2002 and 2006, this line still operates essentially unchanged since the 1930s. |
| New Orleans | New Orleans RTA | New Orleans Streetcars | 1835 | 22.3 mi (35.9 km) | 4 | Heritage streetcar | The St. Charles Avenue Line is the oldest continuously operating street railway system in the world, beginning operation as a horse-drawn system in 1835; the line was electrified in 1893. Three additional lines built to more modern standards have been added since 1988. |
| Philadelphia | SEPTA | SEPTA subway–surface trolley lines | 1906 | 19.8 mi (31.9 km) | 5 | Light rail / Streetcar | The subway–surface trolley lines began operation as a mixed subway/streetcar system in 1906, and have continued operation essentially unchanged since that time. |
| Philadelphia | SEPTA | Media–Sharon Hill Line | 1906 | 11.9 mi (19.2 km) | 2 | Light rail / Streetcar | SEPTA Routes 101 & 102 (the Media-Sharon Lines) began operation as rail lines in mostly exclusive rights-of-way (light rail) in 1906, and have also operated mostly unchanged since then. |
| Philadelphia | SEPTA | SEPTA Route 15 | 1859 | 8.4 mi (13.5 km) | 1 | Heritage streetcar | SEPTA Route 15 (the Girard Avenue Line) started as a horse car line, electrified in 1895. It was replaced with buses in 1992, but service on the line with heritage streetcars resumed in 2005. |
| Pittsburgh | Pittsburgh Regional Transit | Pittsburgh Light Rail | 1903 | 26.2 mi (42.2 km) | 2 | Light rail | Began as a streetcar network, but was partially converted to light rail. By the 1970s, most routes were converted to bus, and the remaining streetcar lines (all of which still used the 1904 Mt. Washington Transit Tunnel) were converted to light rail. This included the construction of a new 1.1 miles (1.8 km) downtown tunnel. The converted system partially opened for service in 1984. |
| San Francisco | MUNI | Cable cars | 1878 | 5.2 mi (8.4 km) | 3 | Heritage cable car | World's last manually operated cable car system. Of the 23 lines established between 1873 and 1890, only three remain. While the cable cars are used to a certain extent by commuters, the vast majority of their seven million annual passengers are tourists. |
| San Francisco | MUNI | Muni Metro | 1912 | 35.7 mi (57.5 km) | 7 | Light rail / Streetcar | Began as a streetcar network, but was partially converted to light rail. While most of San Francisco's original streetcar lines had been converted to buses, five lines with dedicated rights-of-way could not be converted. The streetcars were partially converted to light rail in 1980, sending the lines into the Market Street subway. The lines still operate as streetcars on surface streets. The T Third Street and S Shuttle lines added later are true light rail. |
| San Francisco | MUNI | E Embarcadero / F Market & Wharves | 1982 | 7.7 mi (12.4 km) | 2 | Heritage streetcar | Established in 1982 during a closure of the cable car system for refurbishment, to provide an alternative tourist attraction. Streetcars operated on the Market Street tracks recently abandoned by the streetcar lines that became the Muni Metro. Service proved popular and was retained and expanded. |

## "Second-generation" modern systems

Inspired by the German Stadtbahn (English: city rail) systems, the second generation of modern light rail systems generally have large multi-car trains that travel larger distances, make fewer stops, and run at least partly on exclusive rights-of-way. The first was the San Diego Trolley, which opened in 1981.
| City/Area served | State | System | Year opened | System length | Stations | Lines | Year last expanded |
| Baltimore | Maryland | Baltimore Light Rail | 1992 | 33 mi (53 km) | 33 | 3 | 2006 |
| Buffalo | New York | Buffalo Metro Rail | 1984 | 6.4 mi (10.3 km) | 14 | 1 | 1986 |
| Charlotte | North Carolina | LYNX Blue Line | 2007 | 19.3 mi (31.1 km) | 26 | 1 | 2018 |
| Dallas | Texas | Dallas Area Rapid Transit (DART) | 1996 | 93 mi (150 km) | 64 | 4 | 2016 |
| Denver | Colorado | RTD Light Rail | 1994 | 60.1 mi (96.7 km) | 57 | 6 | 2019 |
| Houston | Texas | METRORail | 2004 | 22.7 mi (36.5 km) | 39 | 3 | 2017 |
| Jersey City | New Jersey | Hudson–Bergen Light Rail (NJ Transit) | 2000 | 17 mi (27 km) | 24 | 3 | 2011 |
| Los Angeles | California | Metro Rail A, C, E, & K lines | 1990 | 94.4 mi (151.9 km) | 87 | 4 | 2024 |
| Minneapolis–Saint Paul | Minnesota | Metro: Blue & Green lines | 2004 | 21.8 mi (35.1 km) | 37 | 2 | 2014 |
| Norfolk | Virginia | The Tide | 2011 | 7.4 mi (11.9 km) | 11 | 1 | — |
| Phoenix | Arizona | Valley Metro Rail | 2008 | 29.8 mi (48.0 km) | 41 | 1 | 2024 |
| Portland | Oregon | MAX Light Rail | 1986 | 60 mi (97 km) | 97 | 5 | 2015 |
| Sacramento | California | SacRT light rail | 1987 | 42.9 mi (69.0 km) | 53 | 3 | 2015 |
| St. Louis | Missouri and Illinois | MetroLink | 1993 | 46 mi (74 km) | 37 | 2 | 2006 |
| Salt Lake City | Utah | TRAX | 1999 | 44.8 mi (72.1 km) | 51 | 3 | 2013 |
| San Diego | California | San Diego Trolley | 1981 | 65 mi (105 km) | 62 | 4 | 2021 |
| San Jose | California | VTA light rail | 1987 | 42.2 mi (67.9 km) | 62 | 3 | 2005 |
| Seattle | Washington | Link light rail | 2009 | 31.25 mi (50.29 km) | 27 | 2 | 2024 |
| Tacoma | Washington | T Line (Link light rail) | 2003 | 4.0 mi (6.4 km) | 12 | 1 | 2023 |

## Streetcar systems

Modern streetcar systems generally have smaller single-car trains that travel on short routes with frequent stops in lanes that are shared with automobile traffic (street running). The first was the Portland Streetcar, which opened in 2001. Some are heritage streetcar lines, which run vintage or historic-replica vehicles.
| City/Area served | State | System | Year opened | System length | Stops | Lines | Year last expanded | System type |
| Atlanta | Georgia | Atlanta Streetcar | 2014 | 2.7 mi (4.3 km) | 12 | 1 | — | Modern |
| Charlotte | North Carolina | CityLYNX Gold Line | 2015 | 4 mi (6.4 km) | 17 | 1 | 2021 | Modern |
| Cincinnati | Ohio | Connector | 2016 | 3.6 mi (5.8 km) | 18 | 1 | — | Modern |
| Dallas | Texas | Dallas Streetcar | 2015 | 2.45 mi (3.94 km) | 6 | 1 | 2016 | Modern |
| Dallas | Texas | M-Line Trolley | 1989 | 4.6 mi (7.4 km) | 40 | 1 | 2015 | Heritage |
| Detroit | Michigan | QLine | 2017 | 3.3 mi (5.3 km) | 20 | 1 | — | Modern |
| El Paso | Texas | El Paso Streetcar | 2018 | 4.8 mi (8 km) | 27 | 1 | — | Heritage |
| Kansas City | Missouri | KC Streetcar | 2016 | 2 mi (3.2 km) | 16 | 1 | — | Modern |
| Kenosha | Wisconsin | Kenosha Streetcar | 2000 | 2 mi (3.2 km) | 17 | 1 | — | Heritage |
| Little Rock | Arkansas | Metro Streetcar | 2004 | 3.4 mi (5.5 km) | 15 | 1 | 2007 | Heritage |
| Memphis | Tennessee | MATA Trolley | 1993 | 6.3 mi (10.1 km) | 25 | 3 | 2021 | Heritage |
| Milwaukee | Wisconsin | The Hop | 2018 | 2.5 mi (4 km) | 21 | 2 | 2023 | Modern |
| Oklahoma City | Oklahoma | Oklahoma City Streetcar | 2018 | 4.6 mi (7.4 km) | 22 | 2 | — | Modern |
| Portland | Oregon | Portland Streetcar | 2001 | 7.35 mi (11.83 km) | 76 | 2 | 2015 | Modern |
| St. Louis | Missouri | Loop Trolley | 2018 | 2.2 mi (3.5 km) | 10 | 1 | — | Heritage |
| Salt Lake City | Utah | S Line | 2013 | 2 mi (3.2 km) | 7 | 1 | — | Modern |
| Seattle | Washington | Seattle Streetcar | 2007 | 3.8 mi (6.1 km) | 17 | 2 | 2016 | Modern |
| Tampa | Florida | TECO Line Streetcar | 2002 | 2.7 mi (4.3 km) | 11 | 1 | 2010 | Heritage |
| Tempe | Arizona | Tempe Streetcar | 2022 | 3 mi (4.8 km) | 14 | 1 | — | Modern |
| Tucson | Arizona | Sun Link | 2014 | 3.9 mi (6.3 km) | 22 | 1 | — | Modern |
| Washington, D.C. | District of Columbia | DC Streetcar | 2016 | 2.4 mi (3.9 km) | 8 | 1 | — | Modern |

## "Hybrid rail" systems

Hybrid rail systems, routes operating on the national rail network which do not operate with commuter rail characteristics, were introduced in 2004 with New Jersey's River Line. Hybrid rail systems operate vehicles which do not meet Federal Railroad Administration (FRA) guidelines, usually (but not always) small multiple unit railcars like a light rail system, but like commuter rail, they are typically powered by diesel engines over tracks which may be shared with freight trains (which typically only operate overnight, when passenger service has stopped). Unlike most commuter rail systems which only operate during the weekday peak travel periods, hybrid rail systems operate all-day, every day, but typically at longer headways than light rail.
| City/Area served | State | System | Year opened | System length | Stations | Lines | Year last expanded |
| Austin | Texas | CapMetro Rail | 2010 | 32 mi (51 km) | 10 | 1 | 2024 |
| Contra Costa County | California | eBART | 2018 | 10.1 mi (16.3 km) | 3 | 1 | — |
| Camden–Trenton | New Jersey | River Line | 2004 | 34 mi (55 km) | 20 | 1 | — |
| Denton County | Texas | A-train | 2011 | 21 mi (34 km) | 6 | 1 | — |
| Fort Worth | Texas | TEXRail | 2019 | 27.2 mi (43.8 km) | 9 | 1 | — |
| North San Diego County | California | Sprinter | 2008 | 22 mi (35 km) | 15 | 1 | — |

## Systems under construction

The following table lists entirely new light rail, streetcar, or hybrid rail systems under construction. Systems that are in the planning stages but not yet under construction (e.g. Glassboro–Camden Line, Interborough Express, and the Austin CapMetro Rail Project Connect system), are not listed; expansions of existing systems are also not listed here.
| City/Area served | State | System/Line | Planned opening | System length | System type |
| Orange County | California | OC Streetcar | 2025 | 4.1 mi (7 km) | Streetcar |
| Tarrant, Dallas, and Collin counties | Texas | Silver Line | 2025–2026 | 26 mi (42 km) | Hybrid rail |
| Omaha | Nebraska | Omaha Streetcar | 2026–2027 | 3.0 mi (4.8 km) | Streetcar |
| Montgomery and Prince George's counties | Maryland | Purple Line | 2027 | 16.2 mi (26.1 km) | Light rail |