High-mounted stop lamps are required on which type of car manufactured on or after 9/1/1985?

High-mounted stop lamps, commonly known as third brake lights, enhance vehicle visibility and safety during braking. They are specifically mandated for passenger cars manufactured on or after September 1, 1985, in the United States. This requirement aims to reduce rear-end collisions by making a vehicle's braking actions more noticeable to drivers behind it.

Passenger cars were identified for this regulation primarily due to their prevalence on the road and the particular accident risks associated with them. As these vehicles are often lighter and have lower profiles compared to other types, enhancing the visibility of braking signals for following vehicles has a significant safety impact.

While other vehicles like convertibles, SUVs, and pickup trucks can benefit from high-mounted stop lamps, the regulation's specific timing and focus on passenger cars stem from statistical data regarding traffic incidents and the need for uniform safety features across this category of automobiles. Thus, the requirement reflects an important step in automotive safety standards aimed explicitly at passenger vehicles.