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SWUTC Ph.D. Candidate Assistantship Project Description

Analytic Models for Traffic Signal Control

University: Texas A&M University

Principal Investigator:
Kai Yin
Zachry Department of Civil Engineering
(979) 845-9901

Faculty Supervisor:
Yunlong Zhang
Zachry Department of Civil Engineering
(979) 845-9901

Funding Source: USDOT Funds

Total Project Cost: $32,079

Project Number: 600451-00021

Date Started: 9/1/12

Estimated Completion Date: 8/31/13

Project Summary

Project Abstract:
It is the purpose of this dissertation to develop the optimal signal control policy based on the analysis of vehicle delay. We restrict our attention to an isolated intersection rather than a system of signalized intersections. Models are proposed on a theoretic basis, focusing on the random characteristics of traffic. This kind of models is valuable as it shows the magnitude of changes in observed phenomena in response to changes of relevant parameters [2]. Such information is of importance to traffic engineers to adjust the signal timing based on field observations.

Project Objectives:

In this study, two typical cases, the pre-timed and vehicle-actuated signals, are analyzed to answer the following questions: (1). What is the vehicle delay considering left-turn traffic at a pre-timed signal? (2). What are the mean and variance of delay to vehicles at a vehicle-actuated signal? Furthermore, we are going to address the research question: (3). What is the optimal signal control policy over all potentially possible control policies? This optimal policy will tell the maximum possible potential in improving traffic mobility at an intersection.

Task Descriptions:

Task 1 – Review Analytic Methods in Isolated Traffic Signal Control

Task 2 – Pre-timed Signal: Modeling Interactions of Spillback, Blockage and Residual Queues

Task 3Vehicle-actuated Signal: Delay and Queue Analysis

Task 4 – Isolated Signal: Optimal Policy under Heavy Traffic