Sponsor: Oregon Department of Transportation (ODOT)
PI: Dr. Edward Smaglik, Co-PI: Dr. Brendan Russo
Start Date: January, 2020
Proper operation of transportation facilities is dependent upon reliable, accurate traffic sensing equipment; faulty detection equipment can result in unsafe and/or inefficient operation. A recent ODOT project, SPR-781 entitled, “Improving Adaptive / Responsive Signal Control Performance: Implications of Non-Invasive Detection and Legacy Timing Practices” uncovered wide spread issues of data quality irrespective of detector technology (within that work, only 40% (16/40) of examined inductive loop detectors were within 10% of manual count data in a 15 minute analysis period). Given this, and what is currently known about the operational performance of non-invasive detection units, there is a need for policies, procedures, and techniques to identify malfunctioning detection equipment and evaluate the quality of data developed by detectors. Current tools, including those available through new ATC controllers, are able to detect major detector failures by examining the presence, absence, or frequency of data being sent by a detector, but these tools are not able to assess the quality of the information sent; therefore, the health of the detector is commonly unmonitored. For example, detrimental detector behaviors at signalized intersections such as a loop that fails for 3 minutes and works for 1 minute may not send a phase into recall. This partial failure could go unnoticed leading to poor performance and potentially encourage unsafe driver behaviors such as disobedience of signals. Complete failure of a detection zone is identified, but if the detector is operating, it can be hard to discern the quality of the data provided. To address this issue, it is important to develop detector health monitoring procedures, technology agnostic, that can be deployed permanently or in a mobile fashion to identify detection performance issues beyond complete detector failure.