Calibration of automatic performance measures - speed and volume data : volume 1, evaluation of the accuracy of traffic volume counts collected by microwave sensors.

Details

• Creators:
  Saito, Mitsuru ; Schultz, Grant G. ; Chang, David K.
• Corporate Creators:
  Brigham Young University. Dept. of Civil and Environmental Engineering
• Corporate Contributors:
  United States. Federal Highway Administration
• Subject/TRT Terms:
  • Signalized intersections
  • Performance measurement
  • Automatic data collection systems
  • Sensors
  • Traffic volume
  • Traffic counts
  • Traffic data
  • Microwave detectors
  • Evaluation
  • Accuracy
• Publication/ Report Number:
  UT- 15.14
• Resource Type:
  Tech Report
• Geographical Coverage:
  Utah
• Corporate Publisher:
  Utah. Dept. of Transportation
• Abstract:
  Over the past few years, the Utah Department of Transportation (UDOT) has developed a system called the ; Signal Performance Metrics System (SPMS) to evaluate the performance of signalized intersections. This system ; currently provides data summaries for several performance measures including: 1) Purdue Coordination Diagram, 2) ; Speed, 3) Approach Volume, 4) Purdue Phase Termination Charts, 5) Split Monitor, 6) Turning Movement Volume ; Counts, 7) Arrivals on Red, and 8) Approach Delay. There is a need to know the accuracy of the data that are being ; collected by the Wavetronix SmartSensor Matrix and displayed in the SPMS. The TAC members determined that ; the following factors would affect the accuracy of radar-based traffic sensors the most: sensor position, number of ; approach lanes, and volume level. The speed limit factor was added to the study after most of the data collection ; was completed. The purpose of this research was to collect data at various intersections to determine the accuracy ; of the data collected by the Wavetronix SmartSensor Matrix. A Mixed Model Analysis of Variance (ANOVA) was ; employed to analyze the effects that each factor had on the accuracy of the traffic volume count. A total of 14 tests ; were performed to examine the effects of the factors on traffic volume count accuracy. The sensor position factor ; was not found to be a statistically significant factor affecting the accuracy of traffic volume counts. The effect of ; speed limit on traffic volume count accuracy was determined to be inconclusive due to the lack of samples to be ; tested. The remaining, volume level and number of approach lanes, were found to have a statistically significant ; effect on the accuracy of traffic volume counts. Based on these two factors, a table of accuracy ranges was created ; to meet the needs of UDOT to present accuracy ranges on the SPMS website. This table includes the mean, 95 ; percent confidence interval of the mean, standard deviation, number of samples, and the minimum number of ; samples needed. In general the sensor provides accuracy level that is ready for practical use by traffic engineers.
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• Format:
  PDF
• Funding:
  14-8290
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/29611/dot_29611_DS1.pdf
• File Type:
  [PDF - 2.21 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:e0f01299cbb7f883adaa2a0c03815355273e9b6b541f485835ddb4d6801c538e