Final answer:
You should not change gears, use the brakes unnecessarily, steer off a straight line, or accelerate unpredictably when crossing railway tracks to avoid accidents.
Step-by-step explanation:
When you are crossing railway tracks, you must not change gears, use the brakes unnecessarily, steer off a straight line, or accelerate unpredictably. It is crucial to approach railway tracks with caution and cross them carefully to avoid accidents. Shifting gears or braking suddenly can stall the vehicle on the tracks, which is dangerous. Similarly, swerving can lead to loss of control, especially on tracks that may be slippery if wet or greasy. Accelerating is also not advised as it may cause the driver to lose control or misjudge the distance to an oncoming train. Always look and listen for trains before crossing and cross quickly and safely without changing speed or direction unnecessarily.