Automatic Detection of Urban Freeway Incidents

Details

• Creators:
  Nuckles, Nelson B. ; Dudek, Conrad L. ; Messer, Carroll J.
• Corporate Creators:
  Texas Transportation Institute. Texas A&M University
• Corporate Contributors:
  Texas Highway Department ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  Alarm Systems Computers Freeway Operations Highway Operations Lane Occupancy Testing Traffic Safety Traffic Surveillance Urban Transportation Vehicle Detectors
• Publication/ Report Number:
  165-12
• Resource Type:
  Tech Report
• Geographical Coverage:
  Texas ; United States
• Edition:
  Interim: September 1971 - May 1973
• Corporate Publisher:
  Texas Transportation Institute. Texas A&M University
• Abstract:
  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. There were no cases of false incident detections during the off-peak periods. The peak period false alarm rate can be reduced to 0.2 percent by utilizing a two-station control criterion in which an incident would not be flagged until two successive upstream stations register critical SND values. The study results showed that the SND model was as effective as the Composite model which was considered to be the best existing model. Since the SND model does not require separate distribution curves for various traffic conditions, it may be a more attractive model for an operational system. Relationships were developed and presented that identify sensor spacing requirements for an incident detection system using a station model.
• Format:
  PDF
• Funding:
  2-18-72-165
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:16636fca20e4749f9c12bdd7a022b0140f75b9b463dc315d4d3234e3fceea7998c9a7829b2976ab63e971f86796af1947d9616f737ab02f2b89920e3dd7bc745
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/85274/dot_85274_DS1.pdf
• File Type:
  [PDF - 2.03 MB ]