AUTOMATIC DETECTION OF URBAN FREEWAY INCIDENTS

An automatic incident detection model using the standard normal deviate (SND) of the control variable (energy or lane occupancy) was proposed, developed, and evaluated. Two strategies were tested using a 3- and 5-minute data base for each control variable. The first strategy (A) required one SND value to be critical; whereas the second strategy (B) required two successive SND values to be critical. Strategy B using lane occupancy with a 5-minute time base was found to produce the best results. It detected 92 percent of the 35 incidents studied during moderate and heavy flow (750-1800 vph per lane) with a computer response time of 1.1 minutes, and operated at a 1.3 percent false alarm rate during the peak period, which can be reduced to 0.2 percent by using a two-station control criterion in which an incident would not be flagged until two successive upstream stations register critical SND values.

• Supplemental Notes:
  • Report on Traffic Management and Control Systems. Sponsored by the Texas Highway Dept., Austin. In cooperation with the Federal Highway Administration, Washington, D.C.
• Corporate Authors:

  Texas Transportation Institute

  Texas A&M University System, 1600 E Lamar Boulevard
  Arlington, TX  United States  76011

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Nuckles, N B
  • Dudek, C L
  • Messer, C J
• Publication Date: 1973-5

Media Info

• Pagination: 90 p.

Filing Info

• Accession Number: 00080234
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: TTI-2-18-72-165-12 Res. Rpt.
• Files: NTIS, USDOT
• Created Date: Jan 29 1975 12:00AM