On August 11, 2004 NHTSA issued a Final Rule that amends the FMVSS 108 Federal lighting standard for motor vehicle turn signal lamps, stop lamps, tail lamps, and parking lamps. These new rules will increase compatibility with similar requirements from the Economic Commission for Europe (ECE). At the same time, these new rules will also improve visibility of these lamps.
This Final Rule is effective on September 1, 2004. Manufacturers will be permitted to comply with either the existing requirements or the new requirements for a period of between seven to 10 years, depending on vehicle type, at which time they will be required to comply with the new requirements.
NHTSA says that this rulemaking will enhance conspicuity of motor vehicles by improving the ability of other motorists to see these lamps from wider angles to the front, side, and rear of the vehicle. In addition to enhancing conspicuity, this rule will improve compatibility of the United States lighting requirements with those of the ECE, as well as the industry consensus standards of the Society of Automotive Engineers (SAE). Consequently, this rule will reduce lighting variations between motor vehicles produced in various world markets, resulting in lower production costs.
The final rule allows vehicle manufacturers to continue to comply with the current visibility specifications of FMVSS No. 108 for some years to come, but they must eventually design their vehicles to comply with one of the two new ECE-derived specifications. Specifically, passenger cars, motorcycles, multipurpose passenger vehicles, trucks, buses, and trailers of less than 2032 mm. (80 in.) in overall width manufactured on and after September 1, 2011, must then comply with one of the two new ECE-derived specifications. Multipurpose passenger vehicles, trucks, buses, and trailers whose overall width is 2032 mm (80 in.) or more must comply with one of these specifications as of September 1, 2014.