Bahnübergänge: Es dauert und dauert – Wie lange sind Schranken geschlossen?

Many people are familiar with this: the barriers at the level crossing lower, the red light starts flashing. And it takes what feels like an eternity before the train finally passes through. Why is that? Stefan Pöting, Head of Railway Technology at TÜV NORD, explains.

The days when a barrier attendant used a crank to open and close barriers at level crossings are long gone. Most of the more than 16,000 level crossings in Germany are actively secured, i.e. equipped with flashing lights, traffic lights and/or barriers. Passively secured level crossings, i.e. those with a St. Andrew's cross only, are only permitted on secondary lines if the train travels at a maximum speed of 80 km/h there. There are no level crossings on high-speed lines where rail vehicles travel faster than 160 km/h; they have been replaced by underpasses or overpasses.

Who “operates” the level crossing?

Barriers will not close on their own, so who will “operate” the level crossing if there is no longer a barrier attendant? The first option is that level crossings are closed and opened by the traffic controller in the signal box. The train on the line is given permission to travel via the track signals. The second option is that level crossings can also be secured by train control, in which case the train itself triggers the light signals and/or the closing of the barriers. Around one kilometer before the level crossing, the train driver is shown whether the level crossing is secured so that he or she can brake before the train reaches the level crossing. As soon as the train has passed the level crossing, the level crossing safety is automatically lifted - unless a train is following in the opposite direction. In this case, road traffic must continue to wait.

“Barriers have to close early, firstly because the train travels fast and secondly because it has long braking distances due to the weight of the trains and the low rolling resistance of the metal tires on the metal rail,” says Stefan Pöting. This rolling resistance is only 20 percent of that of a car tire on an asphalt track. A regional train traveling at 160 km/h covers one kilometer in 22 seconds. Its braking distance during normal service braking is around 1,400 meters, which takes more than a minute. With emergency braking, it still takes 700 meters and 30 seconds. “This is also roughly the minimum time required to secure a level crossing with flashing lights and/or barriers before the train crosses,” says Pöting.

However, according to him, there are two limitations: “Only a few level crossings are secured with their own main signal. And not every train is traveling at 160 km/h.”

If a main signal is located around two kilometers before the level crossing and a regional train is approaching at a speed of 160 km/h, the time between the yellow light and the train passing the level crossing is extended to 90 seconds. If a heavy freight train is approaching at 80 km/h instead of the regional train, the time between the first yellow light and the train crossing is already 180 seconds. If this freight train has also stopped in front of the main signal, it must first pick up speed again. If it were to reach an average speed of 40 km/h on the stretch between the signal and the level crossing, the closing time of the level crossing would be extended by a further 180 seconds, i.e. to a total of 360 seconds, or six minutes. A perceived eternity. If a similarly slow train is coming in the opposite direction, you need a lot of patience in a car, on a bike or motorcycle or as someone on foot. “But it's better to wait patiently and possibly arrive too late than never,” says Pöting.

Although there is the so-called 240-second rule, according to which a level crossing should not be closed for longer than these 240 seconds (i.e. four minutes), it can certainly take longer for technical reasons - for example, if there is a station nearby where a train stops, or if there is a complex rail system near the level crossing.

Incidentally, this 240-second rule does not mean that the level crossing may be crossed after the time has elapsed, even if the barriers are closed or the red light is on. The level crossing is only clear when the safety devices are switched off or employees of the railroad or the federal police clear the route for road users.

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