Traffic signal timing plans are typically designed from manual turning movement counts collected during peak periods. Once systems are constructed and settings are implemented, they receive maintenance on fixed schedules that can extend to several years. Public feedback (e.g., phone calls) is in many cases the primary channel by which information about the system is obtained by the agency. System assessment is often conducted by collectinga new small data sample and repeating the design process. One common and frustrating result is that the same settings are frequently recommended bythe design software, even when problems are known to exist. This paper illustrates how fundamental traffic engineering concepts can be integrated with traffic signal system detection and controller status information to provide outcome based arterial system performance measures. These outcome based performance measures characterize the operation of a signal system and provide a data set that can be used to identify and prioritize opportunities for operational improvements in the system. This paper focuses on performance measures oriented analysis of capacity utilization. A consistent set of performance measures used across a signal network would impact traffic signal operations at two distinct levels. At the regional or district level, it would provide a continuously updated list of problem areas with greater accuracy than telephone reports. At the agency jurisdiction level, it would provide quantitative data for prioritizing resources across multiple districts, and by time of day.
Abstract