Tram-train

A tram-train is a light-rail public transport system where trams run through from an urban tramway network to main-line railway lines which are shared with conventional trains. This combines the tram's flexibility and accessibility with a train's greater speed, and bridges the distance between a main railway stations and a city centre.

There is also a train-tram, which is a train modified to also run on tramlines. Generally, the tram-train and train-tram are interchangeable, although a train-tram is based on a train design modified to also run as a tram and a tram-train is based on a tram design modified to also run on a train line.

The tram-train concept was pioneered with the Karlsruhe model in Germany, and has since been adopted on projects such as the RijnGouweLijn in the Netherlands, at Mulhouse in France and in Kassel and Saarbrücken in Germany.

The tram-train often is a type of interurban, i.e. they link separate towns or cities. according to George W. Hilton and John F. Due's definition.

Most tram-trains are standard gauge, which facilitates sharing track with main-line trains. Exceptions include Alicante Tram and Nordhausen which are metre gauge.

Tram-train vehicles are dual-equipped to suit the needs of both tram and train operating modes, with support for multiple electrification voltages if required and safety equipment such as train stops and other railway signalling equipment. The Karlsruhe and Saarbrücken systems use ‘PZB’ or ‘Indusi’ automatic train protection, so that if the driver passes a signal at stop the emergency brakes are applied.

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Wikipedia