01495778

Component

https://doi.org/10.3141/2355-02

http://scholar.google.com...ohal&publication_year=2013

Choosing an appropriate objective function in optimizing traffic signals in urban transportation network is not a simple and straightforward task because the choice likely will affect the set of constraints, modeling variables, obtained outputs, and necessary computer and human resources. A methodology for selection of an appropriate objective function for the problem of signal timing optimization was developed. The methodology was applied to a realistic case study network under four demand patterns (symmetric, asymmetric, undersaturated, oversaturated). Selection is made from a pool of five candidates: minimizing the delay, minimizing the travel time, maximizing the throughput-minus-queue, maximizing the number of completed trips (or trip maximization), and maximizing the weighted number of completed trips (or weighted trip maximization). Findings indicate that for all demand patterns, weighted trip maximization improved network performance compared with the other objective functions. Weighted trip maximization reduced system total delay by 0.1% to 5.2% in symmetric undersaturated demand, by 1.0% to 2.4% in asymmetric undersaturated demand, by 1.2% to 16.6% in symmetric oversaturated demand, and by 11.7% to 27.4% in asymmetric partially oversaturated demand. These figures indicate that the weighted trip maximization objective function is the most suitable of the candidates in oversaturated conditions, especially when demand is not symmetric. Throughput-minus-queue and trip maximization were the second most suitable objective functions for oversaturated conditions, and trip maximization was slightly more suitable when demand was asymmetric.

01495450

English

pp 10-19

2013

Transportation Research Record: Journal of the Transportation Research Board

9780309286725

Print

Figures; References; Tables

Case studies; Networks; Optimization; Traffic delays; Traffic queuing; Traffic signal timing; Travel demand; Travel time

Objective function

Highways; Operations and Traffic Management; I73: Traffic Control

TRIS, TRB, ATRI

Oct 18 2013 9:38AM

• Coordinated Optimization of Signal Timings for Intersection Approach with Presignals
• Development and Use of Critical Functional Requirements for Controller Upgrade Decisions
• Increasing the Capacity of Signalized Intersections with Dynamic Use of Exit Lanes for Left-Turn Traffic
• Longitudinal Performance Measures for Assessing Agencywide Signal Management Objectives
• Optimized Advance Detector Configuration for Option Zone Protection at High-Speed Signalized Intersections
• Probability Model for Understanding the Effects of Detector Delays on Right-Turn-on-Red Traffic
• Revisiting the Cycle Length: Lost Time Question with Critical Lane Analysis
• Simple Methodology for Estimating Queue Lengths at Signalized Intersections Using Detector Data
• Two-Step Optimization Model for Dynamic Lane Assignment at Isolated Signalized Intersections