Developing a Quality of Signal Timing Performance Measure Methodology for Arterial Operations

US Transportation Collection2020PDFTech ReportTian, ZongWang, AoboXu, HaoUniversity of Nevada, Reno. Center for Advanced Transportation Education and ResearchNevada. Department of TransportationNevada. Dept. of TransportationNevadaUnited StatesArterial highwaysEvaluation and assessmentMethodologyMetrics (Quantitative assessment)Traffic signal timingPerformance measurementTrajectorySignal CoordinationPerformance Index607-17-803Final ReportThe report covers the work performed under NDOT\u2019s research contract #607-17-803, which involved the development of a quality of signal timing performance measure methodology for arterial operations. Evaluating the benefits of traffic signal re-timing is of an increasing interest to transportation policymakers, operators, and the public, as integrating performance measurements with agencies\u2019 daily signal timing management has become a top priority. The current state of practice and research was reviewed first, revealing an urgent research need for the development of a methodology that focuses on arterial-level signal timing performance assessments. Accordingly, arterial travel-run speed and stop characteristics, which can be extracted from vehicles\u2019 GPS travel trajectories, were selected to measure the quality of arterial signal timing in this research. Two performance measures were then defined based on speed and stop characteristics: the attainability of ideal progression (AIP) and the attainability of user satisfaction (AUS). In order to determine AIP and AUS, a series of investigations and surveys were conducted to characterize the effects of non-signal-timing-related factors (e.g., arterial congestion level) on average travel speed as well as how stops may affect travelers\u2019 perceived quality of signal timing. Considering the effects of non-signal-timing-related factors, an AIP metric can be computed based on an arterial\u2019s operating speed and ideal progressive speed. The AUS metric accounted for the changes in the perceived quality of signal timing due to various stop circumstances. Based upon AIP and AUS, a grade-based performance measurement methodology was developed. The methodology included AIP scoring, AUS scoring, and two scoring adjustments. The two types of scoring adjustments further improved the performance measurement results by considering factors such as cross-street delays, pedestrian delays, and arterial geometric conditions. The process for implementing the proposed methodology was outlined in this report, including data collection and preliminary examination of applicable conditions. Case studies based on real-world signal re-timing projects were presented to demonstrate the applicability of the proposed methodology in practice. This research may have a great potential for enhancing agencies\u2019 capabilities of cost-effectively monitoring the quality of arterial signal timing, proactively addressing signal timing issues, and reporting the progress and outcomes in a timely, concise, and intuitive manner.143