Federal Highway Administration Office of Operations and Resource Center. Some material in this monograph was compiled from previous studies that were made possible under National Cooperative Highway Research Program project 3-79a, INDOT State Planning and Research (SPR) projects, Indiana LTAP projects, and USDOT through Small Business Innovation Research (SBIR) projects with Traffax, Inc., and through a joint research project with Marshall University. We would like to thank Rick Schuman and colleagues at Inrix, Inc., for provision of sample vehicle trajectory data in Chapter 7. We are grateful to these sponsors and research partners for their support over the years.The contents of this paper reflect the views of the authors, who are responsible for the facts and the accuracy of the data presented herein, and do not necessarily reflect the official views or policies of the sponsoring organizations. These contents do not constitute a standard, specification, or regulation. CopyrightCopyright 2015 by Purdue University. All rights reserved.Print ISBN: 978-1-62260-376-3 ePUB ISBN: 978-1-62260-377-0 ABSTRACT INTEGRATING TRAFFIC SIGNAL PERFORMANCE MEASURES INTO AGENCY BUSINESS PROCESSESThis report discusses uses of and requirements for performance measures in traffic signal systems facilitated by high-resolution controller event data. Uses of external travel time measurements are also discussed. The discussion is led by a high-level synthesis of the systems engineering concepts for traffic signal control, considering technical and nontechnical aspects of the problem. This is followed by a presentation of the requirements for implementing data collection and processing of the data into signal performance measures. The remaining portion of the report uses an example-oriented approach to show a variety of uses of performance measures for communication and detector system health, quality of local control (including capacity allocation, safety, pedestrian performance, preemption, and advanced control analysis), and quality of progression (including evaluation and optimization).

Overview of Study LocationThe location used to demonstrate the use of the Abstract Graphical Performance Measures for Practitioners to Triage Split Failure Trouble CallsDetector occupancy is commonly used to measure traffic signal performance. Despite improvements in controller computational power, there have been relatively few innovations in occupancy-based performance measures or integration with other data. This paper introduces and demonstrates the use of graphical performance measures based on detector occupancy ratios to verify potential split failures and other signal timing shortcomings reported to practitioners by the public. The proposed performance measures combine detector occupancy during the green phase, detector occupancy during the first five seconds of the red phase, and phase termination cause (gap out or force off). These are summarized by time of day to indicate whether the phase is undersaturated, nearly saturated, or oversaturated. These graphical performance measures and related quantitative summaries provide a first-level screening and triaging tool for practitioners to assess user concerns regarding whether sufficient green times are being provided to avoid split failures. They can also provide outcome-based feedback to staff after making split adjustments to determine whether operation improved or worsened. The paper concludes by demonstrating how the information was used to make an operational decision to re-allocate green time that reduced the number of oversaturated cycles on minor movements from 304 to 222 during a Thursday 0900-1500 timing plan and from 240 to 180 during a Friday 0900-1500 timing plan.

Transgender people who experience serious mental illness represent a uniquely vulnerable population. Because of limited research, however, recommendations for treating this population are scarce. In this article, the authors describe the challenge of recognizing gender dysphoria in people with serious mental illness. They then discuss why existing evidence and clinical experience support provision of gender-affirming medical and surgical treatments for transgender people who have serious mental illness and also demonstrate capacity to make informed medical decisions. More research is needed to develop evidence-based treatments and programs for transgender people with serious mental illness.

Agencies often find it difficult to justify investments in active traffic management. Historically, it has been a challenge to obtain data that would help make the case for those investments. While new data sources have emerged recently, there remains very little documentation of the potential long term benefits from signal retiming using associated performance measures. This study presents a use case for an active traffic management strategy on a signalized corridor over a 5-year period, during which traffic volumes increased by approximately 36%, and offset optimization was performed every 2-3 years. Despite the considerable volume growth, arrivals on green were increased by more than 41%, and the percentage of vehicles arriving on green increased by 10%, a gain of 6 percentage points. Furthermore, drivers experienced an average of 5% reduction in travel time and travel time reliability costs after each optimization. This resulted in a total user benefit over the 5-year period of approximately $3.6 million. Agencies can utilize these strategies to quantitatively assess how traffic performance and signal timing degrade over time, in a manner similar to physical infrastructure assets. The results highlight the benefits and associated business case of adopting a long-term active traffic management strategy, based on datadriven performance monitoring and decision making.

No abstract