Final answer:
Vehicles required to stop at highway-rail grade crossings include those carrying hazardous materials and passenger-carrying vehicles, making the correct answer 'Both A and B'.
Step-by-step explanation:
Both A and B are required to stop at highway-rail grade crossings. Federal regulations mandate certain vehicles to stop at railroad crossings to ensure safety.
A. A tanker transporting a Division 2.3 Chlorine falls under hazardous materials regulations, and vehicles carrying such materials are required to stop at railroad crossings to assess the situation and proceed only when it is safe.
B. A motorcoach carrying 19 passengers is considered a commercial motor vehicle, and commercial drivers are generally required to stop at railroad crossings to ensure the safety of their passengers.
Stopping at railroad crossings is a critical safety measure to prevent accidents and collisions with trains.
Understanding and adhering to regulations regarding stops at highway-rail grade crossings are essential for drivers, particularly those operating vehicles carrying hazardous materials or passengers. Compliance with these regulations contributes to overall road and rail safety.