Freeway surveillance and control systems obtain most of their input information from discrete vehicle presence sensors. Performance measures, for both on-line control and off-line evaluation, must be determined from the presence data. The most significant measures include speed, flow rate, and detector occupancy. To obtain accurate estimates of the measures requires that several parameters be established for the sensor configuration and for the computational algorithms. These include size of detection zone, detector scanning interval, vehicle lengths, speed distribution characteristics, averaging period, and degree of feedback of the average speed into the calculation of individual speeds. The relationship between these parameters is complex and does not lend itself to a simple analytical treatment. Therefore, a simulation model was developed to analyze the effect of the various parameters on the accuracy of the measurements obtained from discrete sensors. Through the simulation model, several relationships were investigated. Based on these relationships, some important conclusions and recommendations are offered for the design and operation of discrete sensor systems for freeway surveillance. /Author/

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: pp 19-28
  • Monograph Title: Freeways, automatic vehicle identification, and effects of geometrics
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00153154
  • Record Type: Publication
  • ISBN: 0309025702
  • Files: TRIS, TRB
  • Created Date: May 31 1977 12:00AM