What is the speed limit when approaching a railroad crossing without warning devices and visibility is limited?

Answer: C — 15 MPH

When approaching a railroad crossing that lacks any warning devices and the visibility is restricted, the speed limit is set at 15 MPH. This limit is established to ensure the safety of drivers and passengers, allowing them to stop safely if a train is approaching, especially when visibility is poor. The slower speed provides drivers with more time to react to potential hazards, enabling them to ensure that the crossing is clear before proceeding. This cautionary speed limit is crucial in areas where standard signals or signs are absent, as it emphasizes the importance of being vigilant and prepared for any oncoming trains. By adhering to this reduced speed, drivers can make more informed decisions and significantly decrease the risk of accidents at railroad crossings.