Yes—most jurisdictions require a center high-mounted stop lamp, commonly called a third brake light, on new vehicles. The rule and its scope vary by country and vehicle type, so specifics depend on where the vehicle is sold or operated.
Regional requirement overview
The presence of a third brake light is a widespread safety standard, but the exact dates when it became mandatory, which vehicles it applies to, and how strictly it is enforced differ from place to place. The overview below outlines the general framework in major markets and highlights where to check local regulations.
United States
In the United States, the law requires a center high-mounted stop lamp on most new motor vehicles. The requirement is enforced under Federal Motor Vehicle Safety Standard 108 (FMVSS 108). The CHMSL became mandatory for the 1986 model year and later for new light-duty vehicles, including passenger cars, trucks, SUVs, and vans. The lamp must be clearly visible to rear traffic and function properly when brakes are applied.
Key implications:
- Most new passenger cars, light trucks, SUVs, and vans sold in the U.S. must have a CHMSL.
- Manufacturers must ensure CHMSL visibility under normal operating conditions.
- Older vehicles manufactured before 1986 may not have a CHMSL and are not retroactively required to be equipped with one, though safety inspections may vary by state.
In practice, the rule impacts new-vehicle compliance and manufacturing standards; it does not automatically require retrofitting older cars.
Canada and other North American markets
Canada follows a federal standard (CMVSS 108) that mirrors the U.S. FMVSS 108, requiring CHMSL on new vehicles sold in Canada. The rule is enforced at the federal level, and retrofitting older vehicles is generally not mandated. Provincial or territorial inspection rules may influence compliance for used vehicles in some cases.
European Union and Europe
In Europe, a center high-mounted stop lamp is required on new passenger cars and many light commercial vehicles under UNECE regulations that member states adopt. The CHMSL requirement was introduced in the late 1980s and became widely implemented during the 1990s across EU and EEA countries. As with the United States, the lamp must be functional and clearly visible to drivers behind the vehicle.
Australia and other regions
Australia's design rules (Australian Design Rules, ADRs) require a CHMSL on new vehicles sold domestically, aligning with international practice and the general safety standard. Many other high-income markets around the world have similar requirements, often modeled on UN/ECE or U.S. standards.
What about retrofits and older vehicles?
Retrofits of a third brake light exist but are not universally mandated and may be regulated by local authorities. In the United States, there is no federal requirement to retrofit older vehicles to include a CHMSL, though aftermarket installation can be performed to meet safety or inspection standards where permitted. Some jurisdictions may impose safety inspections that require all lighting to function properly, which can indirectly affect older vehicles without a CHMSL.
Before pursuing retrofits, check with your local department of motor vehicles (DMV) or equivalent authority for rules regarding installation, certification, and inspections.
Why it matters
A third brake light improves rear visibility and helps prevent rear-end collisions by providing a clearer signal when the brakes are applied. For safety authorities, it is a proven measure that complements traditional brake lights and supports timely reactions from following drivers.
Summary
Across major markets, a third brake light is commonly required for new vehicles, but the exact applicability and timelines vary by country. In the United States, Canada, and Europe, the CHMSL has been part of safety regulations for several decades, while other regions align with similar standards. If you are buying, selling, or maintaining a vehicle, verify the applicable regulatory requirements with your local transportation authority or the vehicle manufacturer to ensure compliance.