Research Project Information

Research Project Summary Information

Traffic Control System for Oversaturated Networks(ST4998-1)

KLD Associates, Inc.


Traffic congestion in downtown areas wastes energy, adds to pollutants, and makes downtown locations less attractive to business. This induces further energy waste, because higher density downtown areas generally have higher (non-transportation) energy efficiencies than lower density areas. Most of the traffic control systems installed in the United States depend on historic data rather than responsive on-line real-time control. The theory for responsive on-line control has not existed until recently for traffic congestion arising from oversaturated flow conditions. Advances in computing power and ancillary technologies such as sensors and communications now make it possible to address the traffic flow optimization in congested environments. This project developed and is now field testing the theory and software for responsive real-time traffic control of congested grid networks in urban areas.

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Project Description

Adaptive signal control systems perform real-time optimization of signal cycle, offset and split based on prevailing traffic conditions. Benefits of adaptive signal control include better utilization of roadway capacity, smoother signal coordination, improved level of service, as well as less fuel consumption and polluting emissions. In addition, adaptive signal control significantly reduces the operation and maintenance costs associated with traffic signal re-timing. IMPOST (Internal Metering Policy to Optimize Signal Timing) is a complete package composed of graphical user interface (GUI), optimizer, and simulator for modeling and optimizing traffic signal timings for a network. Unlike many other optimization models, which use a sequential optimization method, IMPOST concurrently optimizes signal phasing plans, phase durations, and signal offsets.


This traffic-control system has the potential to decrease travel times by 20-30% in congested grid networks resulting in fuel savings of an average 0.023 gallons per vehicle mile, or approximately 25 million gallons a year, in Manhattan. Fifty new jobs may be created for installing, servicing, marketing, and upgrading this product.

Project Results

The resulting traffic control system was highlighted at the Intelligent Transportation Systems World Congress in NYC in 2008, and is currently being tested by the NYC Department of Transportation on the West Side Highway (22 intersections) and on Victory boulevard (4 intersections). Initial results are very promising.


KLD Associates, Inc.
43 Corporate Dr
Hauppauge, NY 11788

Principle Investigator

Edward Lieberman

Universities Involved

Polytechnic University,


Project Type:

Product Development

Technologies Types:


NYSERDA Contact Information

Joseph Tario


R&D -Transport & Power Systems

Contract Details

Start Date: 1/11/2010
Project Status: Active
Contract Number: ST4998-1

Last Updated: 3/29/2012