This report contains requirements for the performance and design of air brake systems on trucks, buses, and trailers. Its purpose is to ensure the safe braking performance of these vehicles under normal and emergency conditions. NHTSA asked that the technology review focus on three specific areas: electronic brake actuation or electronically-controlled braking systems (ECBS), air reservoir capacity, and brake performance measurement.
This report provides a technical assessment of Federal Motor Vehicle Safety Standards (FMVSS) 105, Hydraulic and electric brake systems, and FMVSS 135, Passenger car brake systems. The review of these standards is part of a NHTSA’s Regulatory Review Plan to systematically examine all of the FMVSS. The primary thrust of the document is to address two questions: Do the current standards impede emerging technologies in passenger car and light/medium truck braking systems? Do the current standards require modification to adequately regulate emerging technologies? Emerging technologies are reviewed. Estimates of the extent and timing of their influence are made. It is concluded that the standards will not impede emerging technologies in the foreseeable future but could do so in the long term. The view is expressed that the approach of the current standards to ensuring adequate performance under partial-failure conditions may become ineffective as more, and more complex, automatic functions are added to automotive brake systems. A new approach may be required. Seventy-eight references areincluded in an annotated bibliography.
