SWUTC Research Project Description
Title of Project: Dynamic Traffic Assignment Based Trailblazing Guide Signing for Major Traffic Generator
Project Number: 476660-00046
Principal Investigator:
Fengxiang Qiao
(713) 313-1915
P.I. Affiliation: Texas Southern University
qiao_fg@tsu.edu
Project Monitor:
Weijie Zhuo
Houston-Galveston Area Council
(832) 681-2508
Project Status: Active
Date Started: 9/1/08
Estimation Completion Date: 8/31/09
Estimated Cost - Current Fiscal: $28,000
Estimated Cost - Total Planned: $28,000
Project Summary:
Project Abstract:
Trailblazing guide signs, aiming to direct the traveling public to Major Traffic Generators (MTGs) which are normally located in the central core area (e.g. downtown) of the town, can provide directional guidance on a particular road facility from other highways in the vicinity, and therefore enhance mobility and infrastructure efficiency of the roadway system. Currently there is no adequate quantitative analytical instrument on how these signs direct road users progressively along the right route, and what would be the distinction of impacts of unlike sign placement plans. This research aims at developing a novel and hybrid Dynamic Traffic Assignment (DTA) and simulation based model for a local optimal dynamic user equilibrium (DUE) solution for trailblazing signs. The objectives of this research are to: (1) develop suitable DTA algorithms considering guide sign information on Major Traffic Generators; (2) developed suitable simulator and test the algorithm over suitable traffic networks; and (3) synthesize DTA and simulation based procedure for the assessment of trailblazing guide sign placement. The key technology is to develop a novel hybrid analytical and simulation based model that can be converged to a local optimal dynamic user equilibrium (DUE) solution, together with an identified simulator for traffic flow propagation based on the well defined travel patterns. The developed algorithm and resulted assessment procedure are not only awfully imperative in trailblazing guide signing for MTGs, but also indispensable in modern Route Guidance System (RGS) and Advanced Traveler Information System (ATIS), which are important components of the Intelligent Transportation System (ITS).
Project Objectives:
The goal of this research is to develop a DTA based evaluation tool for trailblazing guide signing for MTGs. The objectives of this research are to: (1) develop suitable DTA algorithms considering guide sign information on Major Traffic Generators; (2) developed suitable simulator and test the algorithm over suitable traffic networks; and (3) synthesize DTA and simulation based procedure for the assessment of trailblazing guide sign placement.
Task Descriptions:
Task 1: Conduct Literature Review on Existing DTA models
DTA refers to a broad spectrum of problems, each corresponding to different sets of variables and assumptions, and possessing varying data requirements. Before developing the new hybrid DTA model, a literature review is needed to conduct a thorough review on the existing traffic assignment models, especially on DTA models considering Variable Message Sign (VMS), In-vehicle Guidance System (IGS) and Route Guidance System (RGS). Scientific papers, articles, project reports, handbooks of traffic simulation software, and websites will be searched to acquire a comprehensive understanding of DTA models.
Task 2: Summarize the Limitation of Using Existing models
Based on the literature review, the limitation of using existing DTA model will be summarized for the trailblazing guide signing purpose and possible application of part of the existing technologies to achieve the designed goal. The criteria, such as whether effects of information provided by the guide sign have been reflected by the model and whether the driving behavior under the trailblazing guide signing condition can be incorporated in the model, will be applied to evaluate the merits and drawbacks of existing models for this specific research purpose.
Task 3: Investigate the Effects of Traffic Information on Drivers’ Route Choice Behavior
Since trailblazing guide sign is a kind of traffic information provided for the drivers, the effects of traffic information on drivers’ route choice behavior will be investigated through literature review on technical and research papers, and on communications with experts in the sociological area and experimental test.
Task 4: Develop Suitable Dynamic Traffic Assignment Algorithm
This task includes developing the algorithm considering trailblazing guide signing, proper assumptions, travel pattern definitions, route selection criteria and roadway performance evaluation methods. Since trailblazing guide signs are mainly designed for drivers who are not familiar with the layout of travel network, a special split of driver characteristic will be consider to represent different level of familiarity with the network.
Task 5: Develop Suitable Simulator and Test the Algorithm over Suitable Traffic Networks
After the effort of developing the algorithm, a suitable simulator will be applied to achieve the assignment algorithm. To make a proper decision, a comparison between existing traffic simulation software should be conducted to illustrate the benefits of software and availability of designed function. After the simulation software is selected, experiments will be designed to test the algorithm over one or several traffic networks.
Task 6: Synthesize DTA Procedure for the Assessment of Trailblazing Guide Sign Placement
Based on the experiments in Task 5, Task 6 will synthesize the procedure of dynamic traffic assignment for the assessment of trailblazing guide sign placement over a network.
Task 7: Document Research Results
All the numerical and demonstration results will be documented. A comprehensive report will be prepared to summarize the findings and possible improvements of the whole process.
Index Terms:
Dynamic traffic assignment, Guide signs, Traffic simulation, Dynamic user equilibrium, Trip generation, Direction signs, Research projects