Don't let the name fool you, these are in fact street cars, with a modern touch. Light rail vehicles are called such, to differentiate them from heavy rail trains, also known in many cities as subways, or metro. This can get confusing, as many lightrail lines run into tunnels, and are thus also subway lines.

Some cities, such as Pittsburgh, PA, never got rid off their streetcars, and simply modernized their existing system. Others, like Baltimore, converted underutilized railroad tracks into a rapid transit system.