This research report documents the development models for control of signalized diamond interchanges during oversaturated traffic conditions. Oversaturated traffic conditions occur when the average traffic demand exceeds the capacity of the signal system. The dynamic optimization model proposed is the principal product of this research. The control objective of the dynamic model is to provide maximum system productivity as well as minimum delay for a selected roadway system. A special feature predetermined upper limits.
Increasing individual vehicular traffic is a major concern all around the world. This leads to oversaturation of intersections in no time. Traffic signal control under oversaturated condition is a long lasting challenge. To address this challenge thoroughly, this thesis introduces grade separation at signalized intersections. A lane-based optimization model is developed for the integrated design of interchange ramps (e. g. tunnels), lane markings (e. g. left turns, through traffic, right turns, etc.) and signal timing settings. We take into account two types of lane configurations. One is conventional surface lanes controlled by signals, and the other is grade separated lanes. This problem is formulated as a Mixed Integer Linear Program (MILP), and this can be solved using regular branch in branch out methods. The integer decision variables help in finding if the movement is on grade separated or surface lanes, and also the successor functions to govern the order of signal display. The continuous variables include the assigned lane flow, common flow multiplier, cycle length, and start and duration of green for traffic movements and lanes. The optimized signal time settings and lane configurations are then represented in Vissim simulation. Numerical examples, along with a benefit cost analysis show the great effectiveness of the proposed optimization model.
Internationally, significant attention is given to transport sustainability including planning, design, construction, evaluation, safety and durability of the road system. The 4th International Gulf Conference on Roads: Efficient Transportation and Pavement Systems - Characterization, Mechanisms, Simulation, and Modeling, hosted by the University o
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.
TRB National Cooperative Highway Research Program (NCHRP) Report 731: Guidelines for Timing Yellow and All-Red Intervals at Signalized Intersections offers guidance for yellow change and all-red clearance intervals at signalized intersections. The guidelines provide a framework that can be easily applied by state and local transportation agencies.
