01342936

Component

https://doi.org/10.3141/2259-10

http://scholar.google.com...Zhou&publication_year=2011

The development of a macroscopic simulation tool is presented and tested to quantify the effects of short turn pockets on the sustainable service rate of a signalized intersection. Unlike the theoretical signal capacity, the sustainable service rate includes queue interaction effects and is thus influenced by blockage and spillback at the entrance to a short turn pocket. Previous research on the topic has focused either on the probability of spillback from a short turn pocket or the operation of a system with a single approach lane. No macroscopic model currently available has the ability to analyze throughput reductions due to the effects of short turn pockets on a multilane approach. The model described here uses a series of flow and density restrictions on cells of varying sizes on the approach to the intersection. Results, which indicate sensitivity of the model to turn pocket spillback, blockage, saturation flow rate, pocket length, lane utilization, cycle length, phase sequence, phase overlap, permitted phasing, and time-dependent demand, compare favorably with microsimulation. A phase optimization procedure is described to help efficiently allocate green time for a given set of turn pocket lengths and turn movement percentages. Implications of using the model for signal timing applications are discussed, and recommendations are made on additional model enhancements and testing needs.

01364838

11-0851

English

pp 112-122

2011

Transportation Research Record: Journal of the Transportation Research Board

9780309222952

Print

Figures (8) ; Glossary; References (10) ; Tables (2)

Green interval (Traffic signal cycle); Highway capacity; Length; Macroscopic traffic flow; Signalized intersections; Traffic models; Traffic signal timing; Traffic simulation; Turning lanes

Blockage; Spillback effects (Traffic)

Highways; Operations and Traffic Management; I73: Traffic Control

TRIS, TRB

Feb 17 2011 5:36PM

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• Computational Efficiency of Alternative Algorithms for Arterial Offset Optimization
• Design of Intergreen Times Based on Safety Reliability
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• Detection Performance of Wireless Magnetometers at Signalized Intersection and Railroad Grade Crossing Under Various Weather Conditions
• Development and Evaluation of Optimal Arterial Control Strategies for Oversaturated Conditions
• Estimating Signalized Intersection Delays to Transit Vehicles: Using Archived Data from Automatic Vehicle Location and Passenger Counting Systems
• Evaluating Robustness of Signal Timings for Varying Traffic Flows
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• Improving Safety and Mobility at High-Speed Intersections with Innovations in Sensor Technology
• Integrated Control of Freeway Interchange Model Based on Enhanced Cell Transmission Model
• Intelligent Traffic Signal System for Isolated Intersections: Dynamic Pedestrian Accommodation
• Modeling Variability of Urban Travel Times by Analyzing Delay Distribution for Multiple Signalized Intersections
• New Evidence of Improvements in Dilemma Zone Protection by Detection-Control System
• Predictive Priority for Light Rail Transit: University Light Rail Line in Salt Lake County, Utah
• Quantifying Dynamic Factors Contributing to Dilemma Zone at High-Speed Signalized Intersections
• Quantifying the Benefit of Retiming Traffic Signals Through Multiple Regression
• Reliability, Flexibility, and Environmental Impact of Alternative Objective Functions for Arterial Offset Optimization
• Traffic Signal Optimization with Application of Transit Signal Priority to an Isolated Intersection
• Visual Education Tools to Illustrate Coordinated System Operation