Performance Measures for Traffic Signal Systems


Book Description

This monograph is a synthesis of research carried out on traffic signal performance measures based on high-resolution controller event data, assembled into a methodology for performance evaluation of traffic signal systems. High-resolution data consist of a log of discrete events such as changes in detector and signal phase states. A discussion is provided on the collection and management of the signal event data and on the necessary infrastructure to collect these data. A portfolio of performance measures is then presented, focusing on several different topics under the umbrella of traffic signal systems operation. System maintenance and asset management is one focus. Another focus is signal operations, considered from the perspectives of vehicle capacity allocation and vehicle progression. Performance measures are also presented for nonvehicle modes, including pedestrians, and modes that require signal preemption and priority features. Finally, the use of travel time data is demonstrated for evaluating system operations and assessing the impact of signal retiming activities.




Real-Time Arterial Traffic Signal Performance Measures


Book Description

Increasing demand for highway system capacity compels transportation agencies to extract as much capacity as possible from existing systems. Traffic signals represent a major component of highway systems. Improvement of traffic signal operation requires accurate performance measures. Despite recent improvements in computing technology, traffic signal controllers are currently not able to capture useful performance measures on a cycle-by-cycle basis. This report presents a set of performance measures that could be collected on a cycle-by-cycle basis by a traffic signal controller given the capability to log phase indications and detector actuations. The performance measures investigated here include the volume-to-capacity ratio and arrival type defined by the Highway Capacity Manual. The effectiveness of these performance measures in evaluating operation at a traffic signal is demonstrated in two comparative case studies. The first study investigates the impact of actuating a portion of the coordinated phases at a coordinated arterial intersection. The second study investigates the results of retiming a traffic signal on a coordinated arterial.




Performance-based Management of Traffic Signals


Book Description

Management of traffic signal systems is a critical function for every transportation agency. Thanks to advancements in technology, it is now possible to collect large amounts of data at signalized intersections, leading to the development of dozens of performance measures. The TRB National Cooperative Highway Research Program's pre-publication draft of NCHRP Research Report 954: Performance-Based Management of Traffic Signals provides information to help agencies invest in signal performance measures as part of a comprehensive approach to performance-based management. Supplementary materials to the report include a data dictionary and a PowerPoint presentation.




Development of a Traffic Signal Performance Measurement System (TSPMS)


Book Description

The purpose of this research was to examine the type of performance measures that could be collected at an intersection and develop a system for automatically collecting these performance measures in the field.. We began the research by conducting an assessment ofthe needs of the Texas Department of Transportation (TxDOT) practitioners for an automated system to collect intersection and traffic signal performance measures. We then examined capabilities of some of the existing traffic signal controllers and detection systems to produce the desired performance measures. Based on the findings of the needs assessments and an evaluation of the limitation of the existing detection system, we developed a series of innovative performance measures that practitioners could use to assess traffic operations and the effectiveness of the signal timing at intersections. We then developed a prototype system for automatically collecting these data in the field. We installed the prototype system in two different locations that exhibited different operating characteristics and assessed the ability of the system to collect meaningful and appropriate performance measures.







Measuring Transportation Network Performance


Book Description

This guidebook provides methods for integrating performance measures from individual transportation modes and multiple jurisdictions and for developing new measures, if needed, to monitor transportation network performance. These network performance measures can be used to improve system management, planning, and investment decisions and can be applied to various scenarios. The guidebook should be of immediate use to practitioners in state, regional, or local governments; specially designated authorities; or those in the private sector who are responsible for measuring, operating, and investing in the performance of multimodal and/or multijurisdictional transportation networks.







Urban Street Design Guide


Book Description

The NACTO Urban Street Design Guide shows how streets of every size can be reimagined and reoriented to prioritize safe driving and transit, biking, walking, and public activity. Unlike older, more conservative engineering manuals, this design guide emphasizes the core principle that urban streets are public places and have a larger role to play in communities than solely being conduits for traffic. The well-illustrated guide offers blueprints of street design from multiple perspectives, from the bird’s eye view to granular details. Case studies from around the country clearly show how to implement best practices, as well as provide guidance for customizing design applications to a city’s unique needs. Urban Street Design Guide outlines five goals and tenets of world-class street design: • Streets are public spaces. Streets play a much larger role in the public life of cities and communities than just thoroughfares for traffic. • Great streets are great for business. Well-designed streets generate higher revenues for businesses and higher values for homeowners. • Design for safety. Traffic engineers can and should design streets where people walking, parking, shopping, bicycling, working, and driving can cross paths safely. • Streets can be changed. Transportation engineers can work flexibly within the building envelope of a street. Many city streets were created in a different era and need to be reconfigured to meet new needs. • Act now! Implement projects quickly using temporary materials to help inform public decision making. Elaborating on these fundamental principles, the guide offers substantive direction for cities seeking to improve street design to create more inclusive, multi-modal urban environments. It is an exceptional resource for redesigning streets to serve the needs of 21st century cities, whose residents and visitors demand a variety of transportation options, safer streets, and vibrant community life.




Traffic Signal Timing Manual


Book Description

This report serves as a comprehensive guide to traffic signal timing and documents the tasks completed in association with its development. The focus of this document is on traffic signal control principles, practices, and procedures. It describes the relationship between traffic signal timing and transportation policy and addresses maintenance and operations of traffic signals. It represents a synthesis of traffic signal timing concepts and their application and focuses on the use of detection, related timing parameters, and resulting effects to users at the intersection. It discusses advanced topics briefly to raise awareness related to their use and application. The purpose of the Signal Timing Manual is to provide direction and guidance to managers, supervisors, and practitioners based on sound practice to proactively and comprehensively improve signal timing. The outcome of properly training staff and proactively operating and maintaining traffic signals is signal timing that reduces congestion and fuel consumption ultimately improving our quality of life and the air we breathe. This manual provides an easy-to-use concise, practical and modular guide on signal timing. The elements of signal timing from policy and funding considerations to timing plan development, assessment, and maintenance are covered in the manual. The manual is the culmination of research into practices across North America and serves as a reference for a range of practitioners, from those involved in the day to day management, operation and maintenance of traffic signals to those that plan, design, operate and maintain these systems.