Chicago Transit Authority has installed an electronic control facility to improve operations of its 500-bus owl fleet running between midnight and 5 A.M. Known as Monitor-CTA, the facility consists of a computerized vehicle identity system that will monitor bus schedules, a silent radio alarm system that will instantly transmit the location, bus and run number of an operator in need of help, and a two-way radio system that will provide communications between the bus operator and the dispatcher. At various points between bus routes there are low-powered radio transmitters. Each is assigned an identification number, which is constantly being transmitted at sufficient power to reach a passing bus. The bus receives this radio signal and stores the identity number. Meanwhile, at CTA's headquarters a computer interrogates a different bus every 83.33 milliseconds via a central radio transmitter. The individual bus receiving its specific interrogation code will respond via its radio with its identity (bus and run number) and location (number of the last wayside low-powered radio transmitter passed) and elasped time since passing that transmitter. The computer checks the bus message against the schedule. If out of schedule, a message is printed out on the central dispatcher's CRT display unit.

  • Corporate Authors:

    Simmons-Boardman Publishing Corporation

    P.O. Box 350
    Bristol, CT  United States  06010
  • Publication Date: 1970-7

Media Info

  • Features: Figures; Photos;
  • Pagination: p. 26-31
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00041077
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Mar 9 1974 12:00AM