The Kenworth and Peterbilt Divisions of PACCAR Inc. manufacture over 14% of the Class 8 and above tracks each year. During the past 3 years, a comprehensive test and development program has been implemented at the Corporate Truck R&D Center in Renton, Washington to develop and certify these vehicles in accordance with the requirements of FMVSS No. 121. The object of the following presentation is to show some of the data gathered in the course of this program. Some of the things that take place in the previouly unexplored world of anti-lock systems and high torque brakes are beginning to be understood. In many instances, it has been found that the predictions and design guidelines of "classical" brade theory do not hold true when anti-lock systems and high torque brakes are used. Such effects as increasing brake torque and/or speeding up air timing can result in longer stopping distances and are discussed in this presentation. FMVSS 121 as currently in effect, does not make proper allowance for effects such as these. The primary conclusion is that consistent compliance with the present stringent stopping distance requirements of the Standard is dependent upon factors beyond our control. /HSRI/

Media Info

  • Pagination: p. 159-191

Subject/Index Terms

Filing Info

  • Accession Number: 00131977
  • Record Type: Publication
  • Source Agency: Highway Safety Research Institute
  • Report/Paper Numbers: No. MVSS 121 Proceeding
  • Files: TRIS
  • Created Date: Jun 5 1976 12:00AM