AN EVALUATION OF THE IMPACT RESPONSE OF VARIOUS MOTORIST-AID CALL SYSTEMS

IN AN EFFORT TO ALLEVIATE THE PROBLEM OF FREEWAY INEFFICIENCY RESULTING FROM DISABLED VEHICLES, SEVERAL STATES HAVE INSTALLED THE MOTORIST-AID CALL SYSTEM ON URBAN FREEWAYS. THESE INSTALLATIONS ARE USUALLY SITUATED ADJACENT TO THE ROADWAY, AND COLLISIONS WITH THESE INSTALLATIONS MAY PROVE HAZARDOUS IF ADEQUATE SAFETY FEATURES ARE NOT INCORPORATED. THIS PAPER PRESENTS THE FINDINGS OF ANALYTICAL AND EXPERIMENTAL STUDIES PERFORMED ON THE MARYLAND, ILLINOIS, AND OHIO CALL-BOX CONFIGURATIONS. TWO EXPERIMENTAL TESTS WERE CONDUCTED FOR EACH: A PENDULUM TEST AND A FULL- SCALE CRASH TEST. A PARAMETER STUDY WAS CARRIED OUT WITH THE AID OF A MATHEMATICAL MODEL VERIFIED BY THE FULL-SCALE CRASH TESTS. THE STUDY EMPLOYED VEHICLE WEIGHTS VARYING FROM 2,000 TO 5,000 LB AND IMPACTING VELOCITIES RANGING FROM 20 TO 60 MPH. THE MOST SIGNIFICANT FINDINGS MAY BE SUMMARIZED AS FOLLOWS: (A) THE VEHICLE VELOCITY AND MOMENTUM CHANGES DUE TO THE COLLISION WERE CONSIDERABLY LESS THAN THE ESTABLISHED TOLERABLE LIMITS TO 11 MPH AND 1,100 LB-SEC; (B) VEHICLE DAMAGE WAS MINOR; (C) CALL-BOX DAMAGE IS USUALLY SEVERE, AND THE UNIT GENERALLY HAS TO BE COMPLETELY REPLACED AFTER A COLLISION; AND (D) DETACHMENT OF CALL-BOX ASSEMBLY COMPONENTS DURING A COLLISION MAY PRODUCE A HAZARDOUS CONDITION. /AUTHOR/

  • Record URL:
  • Supplemental Notes:
    • Sponsored by Committee on Traffic Safety Barriers and Sign, Signal and Lighting Supports. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
  • Authors:
    • MARTINEZ, J E
    • Hairston, D E
  • Conference:
  • Publication Date: 1972

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: pp 66-74
  • Monograph Title: Traffic safety barriers, lighting supports and dike slopes
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00203657
  • Record Type: Publication
  • Report/Paper Numbers: No 386
  • Files: TRIS, TRB
  • Created Date: Oct 9 1972 12:00AM