Final answer:
When approaching a railroad crossbuck, one should stop moving and stay stationary until the train has passed by to ensure safety from the atmospheric pressure effects caused by a moving train.
Step-by-step explanation:
When approaching a railroad crossbuck, the appropriate action to take is to stop moving and become stationary until the train passes by.
This is important for safety reasons, as standing close to railroad tracks can be highly dangerous due to the effects of atmospheric pressure when a rapidly moving commuter train is passing. The low-pressure area created by the train can cause a person standing too close to be pulled towards it.
In the context of 'An Occurrence at Owl Creek Bridge,' which is a work of fiction, there is mention of railroad bridges and executions during the Civil War. This narrative provides a dramatic account of the stern measures taken against anyone interfering with railroad infrastructure during that period.