Federal Motor Vehicle Safety Standards; Air Brake Systems

This document makes permanent an existing requirement that trailers with antilock brake systems (ABS) be equipped with an external malfunction indicator lamp. The indicator lamp requirement, which is included in the Federal motor vehicle safety standard that governs air- braked vehicles, was originally scheduled to sunset on March 1, 2009, but had previously been extended to September 1, 2009. The agency had established a sunset date for this requirement in light of the increasing numbers of post-2001 tractors which have an in-cab trailer ABS malfunction lamp, making the external trailer lamp redundant. We are making the requirement permanent in light of additional safety purposes served by the external lamp, including: it not only warns the driver of a malfunctioning trailer ABS, but, unlike the in-cab lamps, indicates which trailer in double and trailer applications has a malfunction, and it assists Federal and State roadside inspectors and maintenance personnel in identifying a malfunctioning trailer ABS. This rulemaking was conducted in response to petitions from the Commercial Vehicle Safety Alliance.