What is part of the exterior test during a bus inspection?

During a bus inspection, confirming the operation of front and rear lights is crucial as it directly impacts the safety and visibility of the vehicle. Properly functioning lights indicate to other drivers and pedestrians the intentions of the bus, such as stopping, turning, or changing lanes. This helps prevent accidents and ensures compliance with traffic laws.

While inspecting the condition of tires and brakes, testing fluid levels in the engine compartment, and checking the driver's seatbelt for functionality are important parts of the overall safety checks, they focus on different aspects of the vehicle's condition and operation rather than the exterior visibility and communication with other road users, which is why the operation of front and rear lights is specifically categorized under the exterior test.