Train crossing

A level crossing is an intersection where a railway line crosses a road or path at the same level, as opposed to the railway line crossing over or under using a bridge or tunnel. The term also applies when a light rail line with separate right-of-way or reserved track crosses a road in the same fashion. Other names include grade crossing, railway crossing, road through railroad, railroad crossing, train crossing, and RXR (abbreviated).

The history of level crossings depends on the location, but often early level crossings had a flagman in a nearby booth who would, on the approach of a train, wave a red flag or lantern to stop all traffic and clear the tracks. Gated crossings became commonplace in many areas, as they protected the railway from people trespassing and livestock, and they protected the users of the crossing when closed by the signalman/gateman. In the second quarter of the 20th century, manual or electrical closable gates that barricaded the roadway started to be introduced, intended to be a complete barrier against intrusion of any road traffic onto the railway. Automatic crossings are now commonplace in some countries as motor vehicles replaced horse-drawn vehicles and the need for animal protection diminished with time. Full, half or no barrier crossings superseded gated crossings, although crossings of older types can still be found in places. New technology is advancing to create new ways of protecting the railway from users of a level crossing, with one of the most recent being obstacle detection scanners fitted to some crossings in Europe.

Some international rules have helped to harmonize level crossing. For instance, the 1968 Vienne convention about signalisation routière:

This has been implemented in many countries, including countries not being part of the Vienna Convention.

Modern trains have a much larger mass relative to their braking capability, and thus a far longer braking distance than road vehicles. With rare exceptions, trains do not stop at level crossings and rely on vehicles and pedestrians to clear the tracks in advance.

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Wikipedia