An adaptive signal control system deployed in Long Island, New York, reduced motorists' fuel consumption by 2,429 gallons per day, reduced average travel time by 19 percent, and cut average emissions by 42 percent.

Experience with adaptive signal control systems in Long Island, New York.

August 2012
Long Island,New York,United States

Summary Information

The New York State Energy Research and Development Authority (NYSDERA) and the New York State Department of Transportation (NYSDOT) implemented a pilot of an adaptive traffic signal system in 2011. The system was installed and tested on nine intersections along a 2.5 mile stretch of the Veterans Memorial Highway (Route 454), a congested suburban arterial on Long Island. The corridor had previously been controlled by a coordinated timing plan. Coordination of the signals had been challenged by unpredictable fluctuations in traffic volume related to the adjacent airport and shipping facility, as well as heavy commuter traffic. The objective of the deployment was to optimize traffic flow by decreasing travel times on the corridor by a minimum of 20 percent during the AM and PM peak periods. The decreased travel time would include the associated benefits of reduced fuel consumption and emissions reductions.

The adaptive traffic signal control system utilizes a processor that incorporates detection with adaptive video monitoring. The software uses the data collected by the cameras to call individual phases at specific signals, but also to adjust the critical system operating parameters such as cycle length, intersection offsets, and green times. The goal of the system is to coordinate the timing for the nine signals in a dynamic manner such that vehicle progression on Route 454 was maximized and delays and stops were minimized.


NYSDOT conducted a before/after study of the traffic control system to evaluate if the system met its intended objectives of decreasing travel times by 20 percent. To evaluate the performance, travel data was collected on the Route 454 corridor during four different weekday time periods (AM, off-peak, midday and PM). The time collection periods were the same for both the before and after installation studies.

Probe vehicles equipped with GPS technology were used to collect detailed time and distance measurements. 117 runs were conducted along the corridor between February and May 2011. Speed, direction, delay, number of stops, and other measures were calculated using data analyzing software. Based on this data, additional outputs were calculated, including fuel consumption, vehicle efficiency, and emissions.

To assess the effectiveness of the system, the "floating car method" was used. The vehicle location is then recorded over time to allow for the calculation of a mean speed. A random arrival procedure was used, meaning that the probe vehicles sometime began traveling from a stop at the intersection, while others arrived during the green phase. The data collection varied also in terms of whether the probe vehicles traveled some or all of the corridor.

Two sets of analyses using different methodologies are provided in this report. The system developer identified different results than the third party evaluator. Each resulted in a different set of findings. The results presented in this snapshot reflect those of the third party evaluator.


Overall, the system generally decreased travel times and stopped times, increased average speeds, reduced stops, and provided vehicle efficiency and emissions benefits. However, the benefits were not equal for the two directions, nor were they uniform over the four analysis time periods.
  • In the eastbound direction, the travel time savings varied. In the AM and midday time periods, travel times decreased by 14 percent and 19 percent respectively. In the PM and off-peak time periods, travel times increased by 1 percent and 5 percent respectively.
  • In the westbound direction, travel times all decreased - by 11 percent in AM, 12 percent in off-peak, 13 percent in midday, and 10 percent in PM.
  • Average travel time was reduced by 19 percent.
  • Fuel consumption was reduced by 2, 429 gallons per day.
  • Average emissions was reduced by 42 percent.

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InSync Adaptive Traffic Control System for the Veterans Memorial Hwy Corridor on Long Island, NY

Author: Steve Elkins, Sr. Project Manager Grant Niehus, Sr. Project Engineer

Published By: New York State Energy Research & Development Authority New York State Department of Transportation

Source Date: August 2012



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Typical Deployment Locations

Metropolitan Areas


traffic signals, adaptive signals

Benefit ID: 2014-00964