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SWUTC Ph.D. Candidate Assistantship Project Description

Platoon-Based Arterial Signal Coordination with Uneven Double Cycling

University: Texas A&M University

Principal Investigator:
Hongmin Zhou
Zachry Department of Civil Engineering
(979) 845-9294

Faculty Supervisor:
Gene Hawkins
Zachry Department of Civil Engineering
(979) 845-9294

Funding Source: USDOT Funds

Total Project Cost: $32,079

Project Number: 600451-00024

Date Started: 1/1/13

Estimated Completion Date: 12/31/13

Project Summary

Project Abstract:
Enabling the uneven double cycle (UDC) scheme in arterial signal coordination raises several problems for the conventional offline coordination optimization. Basically, the UDC scheme adds several new variables to conventional coordination optimization. The scheme needs to choose between single cycling and double cycling for each intersection along the arterial. For each intersection that chooses uneven double cycling, the scheme also needs to determine the green splits of twice-served phases and the sequence of arterial left-turn phases. Moreover, the UDC scheme needs to account for varying traffic demand in the offline optimization process. The scheme actually makes use of the slack time of reduced arterial traffic demand at the minor intersections to service minor street phases; therefore it becomes a challenge to depict demand variation based on narrowly (peak 15 minutes) defined data to optimize coordinated signal timing. Furthermore, realization the benefit of the UDC scheme requires good balance between conflicting optimization objectives, which conventional coordination programs often do not consider. Since cutting a long cycle into two sub-cycles to reduce the delay on minor streets potentially reduces the maximum achievable green bandwidth, maximized bandwidth and minimized total delay on cross streets are two conflicting objectives. Alternative conflicting objectives could be minimized arterial total travel time (or arterial total delay) and minimized total delay on cross streets. A potential solution to these issues is to develop an offline optimization program that properly defines variables and objectives and uses the platoon information as input predicted out of limited data. Such a program will facilitate the practice of the UDC scheme and make better use of current resources.

Project Objectives:
The goal of the research is to develop an offline arterial signal coordination optimization model that enables the scheme of uneven double cycling using offline data. To this end, the research entails the following objectives:

  • predict platoon characteristics based on offline data and identify platoon-based delay function for arterial signal coordination
  • develop a platoon-based optimization model that can properly provide double cycling to reduce delay at minor intersections without compromising good progression
  • evaluate the performance of proposed model and provide guidelines for various field conditions where implementing the UDC scheme is beneficial

Task Descriptions:

Task 1.  Literature Review

Task 2.  Platoon-Based Delay Function Development

Task 3.  UDC-Enabled Arterial Coordination Optimization

Task 4.  Data Collection

Task 5.  Modeling Performance Evaluation