How many high-mounted stop lamps are required on passenger cars?

Passenger cars are required to have one high-mounted stop lamp, also known as a third brake light. This requirement enhances visibility and safety by providing an additional indication of braking to drivers approaching from behind. The high-mounted stop lamp is typically positioned higher than the two standard brake lights located on the lower portion of the vehicle, making it more conspicuous. By having at least one high-mounted stop lamp, the risk of rear-end collisions is reduced, as following drivers have a clearer signal when the vehicle is slowing down or stopping.

In contrast, two or more high-mounted stop lamps are not mandated for passenger cars, as the regulation specifies that a single lamp is sufficient to meet safety standards. This design decision balances functionality with aesthetics and practicality in vehicle design.