Light rail (or light rail transit, abbreviated to LRT) is a form of passenger urban rail transit using rolling stock derived from tram technology[1] while also having some features from heavy rapid transit.
The term was coined in 1972 in the United States, to create an English equivalent for the German word Stadtbahn meaning City railway.[2][3] Different definitions exist in some countries, but in the United States, light rail operates primarily along exclusive rights-of-way and uses either individual tramcars or multiple units coupled together, with a lower capacity and speed than a long heavy rail passenger train or rapid transit system.[4][5][6][7][8]
Narrowly defined it has rolling stock that is similar to a traditional tram, while it operates at a higher capacity and speed and often on an exclusive right-of-way. In broader use, light rail transit includes tram-like operations mostly on streets.[9] A few light rail networks tend to have characteristics closer to rapid transit or even commuter rail; yet only when these systems are fully grade-separated, they are referred to as light metros.