Light rail in North America

Light rail is a commonly used mode of public transit in North America. The term light rail was coined in 1972 by the Urban Mass Transportation Administration (UMTA; the precursor to the U.S. Federal Transit Administration) to describe new streetcar transformations which were taking place in Europe and the United States. The Germans used the term Stadtbahn, which is the predecessor to North American light rail, to describe the concept, and many in UMTA wanted to adopt the direct translation, which is city rail. However, in its reports, UMTA finally adopted the term light rail instead.

From the mid-19th century onwards, horse-drawn trams or horsecars were used in cities around the world. In the late 1880s electrically powered street railways became technically feasible following the invention of a trolley pole system of collecting current by American inventor Frank J. Sprague who installed the first successful system at Richmond, Virginia. They became popular because roads were then poorly surfaced, and 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 only ran in single-car setups. Some rail lines experimented with multiple unit configurations, where streetcars were joined together to make short trains. 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.

After World War II, seven major North American cities (Boston, Newark, New Orleans, Philadelphia, Pittsburgh, San Francisco, and Toronto) continued to operate large streetcar systems. Some of these cities called their modernized systems light rail in an attempt to differentiate it from their existing streetcars particularly cities that continued to operate both the old and new systems. Cleveland, Ohio, maintained an interurban system (e.g. the Blue and Green Lines) that is equivalent to what is now "light rail", which opened before World War I, and which is still in operation to this day.

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