A subway train may move over a crossover at what maximum speed if no speed limiting sign is displayed?

The correct answer is that a subway train may move over a crossover at a maximum speed of 10 MPH if no speed limiting sign is displayed. This speed limit is established primarily to ensure the safety of both the train and the track infrastructure. Crossovers can be complex areas where trains change tracks, and safety protocols necessitate reduced speeds to minimize the risk of derailments and to allow for sufficient stopping distances should any unexpected events occur.

By adhering to this maximum speed of 10 MPH, the operator can maintain greater control of the train during the maneuver, making it easier to respond to any unanticipated conditions. It's important to recognize that areas without speed limiting signs still require a cautious approach, and this speed limit reflects that a balance has been achieved between operational efficiency and safety.