Final answer:
It is unsafe to stop on railroad tracks, as it risks being struck by a train. Traffic safety rules mandate that crossings should be free of vehicles unless they can fully clear the tracks.
Step-by-step explanation:
No, it is not safe to stop on railroad tracks even for a short period of time. Traffic safety rules are clear: railroad crossings should always be kept clear, and you should only cross when you are sure you can get all the way across without stopping. Stopping on the tracks can be extremely dangerous, as it leaves you vulnerable to being struck by an oncoming train.
Emergency situations, like the one described with the pregnant woman, are different cases. Here, Rule Utilitarianism (RU) might suggest that breaking a traffic law is justifiable if it leads to greater overall utility -- in this case, getting to the hospital quickly. However, this should not be confused with regular traffic rules at railroad crossings. In usual conditions, following the rules and waiting until it's safe to cross contributes to overall safety.
Keep in mind, pedestrian safety and traffic flow are important considerations at intersections and train crossings. Many accidents occur because drivers and pedestrians take unnecessary risks. Thus, always prioritize safety and abide by traffic rules and signals to prevent accidents.