What are the three major types of air brakes used in heavy vehicles?

Answer: B — Service brakes, parking brakes, and emergency brakes

The three major types of air brakes used in heavy vehicles are categorized as service brakes, parking brakes, and emergency brakes. Service brakes are the primary braking system utilized during normal driving to slow down or stop the vehicle. They are activated by the driver’s foot on the brake pedal and rely on the air brake system’s pressure to function effectively. Parking brakes are designed to keep the vehicle stationary when it is parked, preventing it from rolling away. These brakes are crucial for securing heavy vehicles, especially on inclines, and are engaged manually. Emergency brakes serve as a backup system to be used in the event that the service brakes fail. They are often designed to activate automatically or can be controlled manually, ensuring that the vehicle can be brought to a stop safely if a problem arises with the primary braking system. In contrast, while disc brakes and drum brakes are types of brake designs that can be found in vehicles, they do not cover the full spectrum of air brake systems as specified in the question. Hydraulic brakes and the other types mentioned do not fit within the air brake classification for heavy-duty applications, as they primarily pertain to other braking systems. Electromagnetic and regenerative brakes are also not applicable within the context of traditional air brake systems used specifically in