A Portable Toolbox to Monitor and Evaluate Signal Operations

Researchers from the Texas Transportation Institute developed a portable tool consisting of a field-hardened computer interfacing with the traffic signal cabinet through special enhanced Bus Interface Units. The toolbox consisted of a monitoring tool and an analysis tool. The monitoring tool monitors and logs relevant events within the cabinet that provide input to analyze intersection operations. These inputs include signal status, detector status, preempt status, and coordination status. The user has to provide the basic signal timing data and coordination data as input data. The analysis tool then analyzes the log files for each day and produces easy to understand reports. The reports are available either in an hourly average format or individual cycle format for a selected time period. The measures of effectiveness (MOEs) presented include phase time, phase failures, queue clearance time, time to service; as well as counts on green, yellow, red, and split utilization during coordinated operations. Preempt data include the type of preempt, time of preempt, and the duration of preempt for each day. Detector failure data include type of detector failure and the time at which the detector failure occurred. The analysis tool analyzes the log files and generates user-specified MOEs in Microsoft Excel® format. This type of format provides the user with an opportunity to further analyze the data in a manner the user considers appropriate.