Before which model year must a passenger car or truck be equipped with at least one tail lamp?

A passenger car or truck must be equipped with at least one tail lamp before the 1960 model year because this requirement was established to enhance the safety and visibility of vehicles on the road. The introduction of safety regulations, including the requirement for tail lamps, aimed to reduce accidents caused by low visibility during nighttime or inclement weather conditions.

By 1960, it became standard practice for manufacturers to include at least one functioning tail lamp on vehicles, ensuring that other drivers could see a vehicle from behind, significantly aiding in preventing collisions. The subsequent model years continued to build on safety features, but the foundational requirement for at least one tail lamp began with vehicles manufactured before 1960. Therefore, the correct context for this safety regulation aligns with the period leading up to 1960, making it the right answer.