When considering whether or not to cross a railway crossing, how long can a train take to stop under full emergency braking?

When evaluating the stopping distance of a train under full emergency braking, it's essential to understand the massive dynamics involved due to a train's size and weight. Trains cannot stop as quickly as cars can, largely because of their momentum and the friction between the wheels and tracks.

Under full emergency braking, the stopping distance for a train can indeed be as long as 2 kilometers or more, depending on various factors such as the train's speed, load, and track conditions. This significant distance emphasizes the importance of being highly cautious at railway crossings, as once a train is in motion, it cannot stop quickly enough to avoid a collision if someone or something obstructs the tracks.

The other distances provided - 1 km, 1.5 km, and 0.5 km - fall short of reflecting the true potential stopping distance for trains under emergency conditions. Understanding this magnitude helps underscore why it is critical to never attempt to cross the tracks if a train is approaching; the time available before it arrives is considerably less than the time needed for it to stop. This knowledge is vital for safety and recognizing the potential dangers of railway crossings.