Details:

Creators:
Saito, Mitsuru ; Schultz, Grant G. ; Chang, David K.
Saito, Mitsuru ; Schultz, Grant G. ; Chang, David K. Less -
Corporate Creators:
Brigham Young University. Dept. of Civil and Environmental Engineering
Corporate Contributors:
United States. Federal Highway Administration
Subject/TRT Terms:
[+]
Accuracy Automatic Data Collection Systems Evaluation Microwave Detectors Performance Measurement Sensors Signalized Intersections Traffic Counts Traffic Data Traffic Volume
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.


Format:
PDF
Funding:
14-8290
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:e0f01299cbb7f883adaa2a0c03815355273e9b6b541f485835ddb4d6801c538e
Download URL:
https://rosap.ntl.bts.gov/view/dot/29611/dot_29611_DS1.pdf
File Type:

Supporting Files

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