Traffic Operations Laboratory

The Traffic Operations Laboratory (TOL) was established to support research in the area of traffic operations with the-state-of-the-art systems including microscopic traffic simulation models, traffic signal timing optimization programs and a hardware-in-the-loop simulation (HILS).

The TOL focuses on the following research activities:

Developing and enhancing the-state-of-the-art traffic signal optimization methods

1. Stochastic optimizations
2. Optimization of controller settings including detector recall, minimum and maximum greens, extension time, detector locations, volume-density parameters, etc. (i.e., beyond cycle, green split, phase sequence and offset)
3. Advanced traffic control algorithm that can support a new environment under vehicle infrastructure integration (VII)
Providing reliable, risk-free and fast evaluation environment using microscopic simulation
4. Calibration and validation of microscopic simulation models
   
5. Application of advanced experimental design methods

Educating students and traffic engineers

1. Workshops in traffic signal optimization methods, simulation model calibration and validation, etc.
2. Laboratory environment for testing various traffic signal controllers, simulation models and traffic signal optimization programs

Equipment

Hardware-in-the loop simulation (HILS)

HILS is one of the most advanced forms of microscopic simulations for traffic signal control systems since it physically links a stochastic simulation model with actual traffic controllers. In this HILS simulation, actual traffic controllers operate traffic signals within the microscopic simulation model such as CORSIM, VISSIM or SimTraffic.

Hardware In The Loop System Structure

The TOL has the following HILS related equipment:

• NEMA TS2 Controllers
• 2070 Controllers
• 170 Controllers
• Controller Interface Devices (CID)
• Signal cabinet & signal head

Rack with 2070 and NEMA TS2 controllers

HILS system with CORSIM, Univ. of Idaho CID and 170 Controller

 
Microscopic simulation models

With the advances in the computational technology, microscopic traffic simulation models have become more realistic than ever before by providing a fast, risk-free and visual evaluation environment. It is believed that microscopic simulation models have been widely adopted as a decision-supporting tool on various traffic operation and management studies.

A Snapshot of VISSIM 3D Animation of West Main Street in Charlottesville, VA

The TOL has the following simulation models:

• CORSIM
• VISSIM
• SIMTRAFFIC
• PARAMICS
• DynaSIM
• TRANSIMS

In addition to microscopic simulation models, the TOL has the following dynamic traffic assignment (DTA) models:

• DynaMIT
• DynaSmart

Traffic Signal Timing Optimization Programs

The traffic signal system is one of the most common facilities being operated by traffic engineers to control traffic in an orderly manner. Traffic signal timing optimization has been recognized as one of the most cost-effective methods for improving accessibility and mobility at urban networks.

The TOL has the following programs:

• TRANSYT-7F
• SYNCHRO
• PASSER-V

Research Efforts

Ongoing or Recent Research

• Development of stochastic traffic signal timing optimization methods
• Evaluation of applied ITS and traffic operational improvement using microscopic simulation models
• Calibration and validation of microscopic simulation models
• Optimization of time-of-day breakpoint for better traffic signal control
• The Next Generation Simulation (NGSIM) program has provided us with amazing amount of traffic and driving behavior data from several locations. While analyzing the data set, a research team at the University of Virginia’s Center for Transportation Studies discovered unrealistic driving behaviors, and reviewing them manually by going over a huge text file was a truly timing consuming task. So the CTS research team developed a visualization tool that can help identify unrealistic data records in NGSIM: NGSIM Analyzer

Future Research Area

• Evaluation of signal timing transition models
• Evaluation of semi-adaptive or traffic responsive signal controls
• Developing software-in-the-loop simulation (SILS)
• Developing new signal control logics

For further information, contact Dr. Park by e-mail: bpark@virginia.edu or call (434) 924-6347.