Field evaluation of smart sensor vehicle detectors at railroad grade crossings - volume 4 : performance in adverse weather conditions.

Details

• Creators:
  Medina, Juan C. ; Benekohal, Rahim F.
• Corporate Creators:
  University of Illinois at Urbana-Champaign. Dept. of Civil and Environmental Engineering
• Corporate Contributors:
  Illinois. Dept. of Transportation. Bureau of Materials and Physical Research ; United States. Federal Highway Administration
• Subject/TRT Terms:
  • Railroad grade crossings
  • Sensors
  • Field tests
  • Microwave detectors
  • Weather conditions
  • Radar vehicle detectors
  • Evaluation and assessment
• Publication/ Report Number:
  FHWA-ICT-15-002 ; ICT-15-002 ; UILU-ENG-2015-2002
• Resource Type:
  Tech Report
• Geographical Coverage:
  Illinois
• Corporate Publisher:
  Illinois Center for Transportation
• Abstract:
  The performance of a microwave radar system for vehicle detection at a railroad grade crossing with quadrant gates was evaluated in ; adverse weather conditions: rain (light and torrential), snow (light and heavy), dense fog, and wind. The first part of this report compares ; the results of the modified system setup in adverse weather conditions with those from good weather conditions (as presented in ; Volume 3 of this study). Then, the results of a re-modified system setup were compared to the results for the modified system setup in ; good and adverse weather conditions. The re-modification was in response to increased detection errors in adverse weather conditions. ; With the modified setup, system performance was sensitive to the adverse weather conditions. In torrential rain, false calls increased to ; 24.82%–27.08% (e.g., May 28 and June 1) when there was some traffic on the crossing. However, when there was torrential rain but ; only one vehicle (e.g., May 31) or no traffic flow (e.g., June 10), the radar units generated 15 false calls on each of those 2 days. For all ; heavy snow datasets combined, missed calls by a single radar unit and by the two radar units working as a combined unit (i.e., ; systemwide) represented 13.51% and 11.66% of the loop calls, respectively. The most severe snow effects were found during freezing ; rain/ice. In dense fog, false calls increased to 11.58%, and all false calls were generated when the gates were moving or in the down ; position. Wind did not affect system performance, and the errors were similar to those in good weather conditions. With the re-modified ; setup, the frequency of errors in heavy rain and heavy snow conditions was reduced and system performance was similar to the good ; weather, light rain, and light snow conditions. In heavy rain, false calls in the re-modified setup were reduced to 2.6% compared with ; 30.5% in the modified setup. This reduction was the result of a significant decrease in the false calls generated without objects in the ; crossing. The re-modified setup eliminated the systemwide missed calls in heavy snow. The re-modified setup also reduced the false ; calls to less than 1% in good weather, light rain, and light snow conditions and practically had no missed, stuck-on, or dropped calls. ; Results indicate that re-modifications improved the performance of detection system.
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• Format:
  PDF
• Funding:
  R27-095
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/28804/dot_28804_DS1.pdf
• File Type:
  [PDF - 1.04 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:1a31e68dc1c039345cc1426e514d66525bf6b7974c73e84f3eb0eb45078cc6db