What is required on the rear of every truck-tractor?

Every truck-tractor must have two red tail-lamps on each side at the rear to ensure visibility and safety, especially in low-light conditions. This requirement is crucial because the red lights serve as indicators to other drivers about the vehicle's position, helping to prevent rear-end collisions. The presence of these tail-lamps is a standard aspect of vehicle safety regulations, which aim to enhance the visibility of large trucks on the road, particularly since they are larger and can be less visible than smaller vehicles.

While additional lighting, such as a white license plate lamp or turn signals, has its own significance for vehicle operation, the specific requirement for two red tail-lamps on each side is fundamental for the identification and safety of truck-tractors on the roadway. The absence of any of these lights would critically compromise the vehicle's visibility and, consequently, the safety of its operation and other road users.