What is the difference between heavy rail, light rail, and streetcars?
There are many types of rail systems, with the most common being heavy rail, light rail, and streetcars. Heavy rail systems, such as Metrorail in Washington, DC, and commuter rail lines, carry the greatest number of people at the fastest speeds, but are also the most expensive to build. Since the costs of tunneling and/or obtaining rights-of-way for heavy rail can be prohibitive, many cities turn to light rail instead; it’s usually less expensive per mile to build than heavy rail, but has less capacity and is somewhat slower. Light rail has an advantage over heavy rail in that it can run either at a separate grade from roadways or on streets in mixed traffic. Light rail vehicles are heavier and longer than streetcars. This makes building them more expensive and integrating them into city streets more difficult. Streetcars are cousins of light rail normally powered by overhead wires on ordinary streets fitted with rails. Slightly smaller than conventional light rail, streetcars typicall