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.







Development of a Real-time Arterial Performance Monitoring System Using Traffic Data Available from Existing Signal Systems


Book Description

Data collection and performance measurement for signalized arterial roads is an area of emerging focus in the United States. As indicated by the results of the 2005 Traffic Signal Operation Self-Assessment Survey, a majority of agencies involved in the operation and maintenance of traffic signal systems do not monitor or archive traffic system performance and thus have limited means to improve their operation. With support from the Transportation Department of Hennepin County, Minneapolis, MN, a system for high resolution traffic signal data collection and arterial performance measurement has been successfully built. The system, named SMART-SIGNAL (Systematic Monitoring of Arterial Road Traffic Signals), is able to collect and archive event-based traffic signal data simultaneously at multiple intersections. Using the event-based traffic data, SMART-SIGNAL can generate timedependent performance measures for both individual intersections and arterials including intersection queue length and arterial travel time. The SMART-SIGNAL system has been deployed at an 11-intersection corridor along France Avenue in south Minneapolis and the estimated performance measures for both intersection queue length and arterial travel times are highly consistent with the observed data.




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.







A Real-time Performance Measurement System for Arterial Traffic Signals


Book Description

The SMART-SIGNAL data collection system has been installed on an 11-intersections arterial corridor along France Avenue in Hennepin County, Minnesota since February 2007. Event-based signal data are being collected in a 24/7 mode and then immediately archived in the SMART-SIGNAL system, thus yielding a tremendous amount of field data available for research. The field study shows that the proposed mathematical models can generate accurate time-dependent queue lengths, travel times, numbers of stops, and other performance measures under various traffic conditions.




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.




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.




Innovative Web Applications for Analyzing Traffic Operations


Book Description

In response to the need to improve road traffic operation, researchers implement advanced technologies and integration of systems and data, and develop state-of-the-art applications to assist traffic engineers. This SpringerBrief introduces three novel Web applications which can be an exceptional resource and a good visualization tool for traffic operators, managers, and analysts to monitor the congestion, and analyze incidents and signal performance measures. The applications offer more detailed analysis providing users with insights from different levels and perspectives. The benefit of providing these automated and interactive visualization tools is more efficient estimation of the local transport networks’ performance, thus facilitating the decision making process in case of emergency events.