Which locations are restricted for employees to walk on?

The correct answer highlights the areas that are explicitly restricted for employee access, particularly identifying running rails, train stops, and transponders as locations where personnel should not walk. This restriction is crucial for maintaining safety and operational integrity.

Walking on running rails can pose significant hazards, as it puts employees in close proximity to moving trains and can lead to dangerous situations. Similarly, train stops and transponders are critical operational elements that require clear access for trains and personnel to maintain a safe and efficient transit environment. Being near these elements invites risks of accidental injury or interference with train operations.

While platforms, service areas, waiting rooms, and maintenance bays each have their own safety protocols, they are not universally prohibited spaces for employee movement. Safety procedures in those areas may allow for walking under certain conditions, provided proper safety measures are followed. In contrast, the direct risks associated with the restricted areas listed make it clear why they are off-limits for employees.