An analysis is developed to determine safe headway on PRT systems that use point-follower control. Periodic measurements of the position error relative to a nominal trajectory provide warning against the hazards of overspeed and unexpected stop. A computer program has been developed to model these hazards for arbitrary safety system design parameters. The results of computer runs indicate that the critical hazard on the main guideway is unexpected stop of a preceding car; on a station entry deceleration ramp, it is overspeed of a following car. The deceleration ramp headways are larger and are more sensitive to system parameters than are the main guideway headways. Typical headways are five seconds on a 30 mph main guideway and 16 seconds on a deceleration ramp for state-of-the-art system parameters. With advanced system parameters and emergency decelerations applicable to well supported, seated passengers, required headways are 2.5 seconds on the main guideway and 3.5 seconds on the deceleration ramp.

  • Corporate Authors:

    Alden Self-transit Systems Corporation


    Transportation Systems Center

    55 Broadway, Kendall Square
    Cambridge, MA  United States  02142

    Urban Mass Transportation Administration

    400 7th Street, SW
    Washington, DC  United States  20590
  • Authors:
    • Whitten, R E
  • Publication Date: 1975-7

Media Info

  • Pagination: 104 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00092423
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: Intrm Rpt., DOT-TSC-UMTA-75-10
  • Contract Numbers: DOT-TSC-421
  • Files: NTIS, TRIS, USDOT
  • Created Date: Nov 5 1982 12:00AM