By Michael Andrako
Deputy Director
Department of Service & Engineering
Department of Service & Engineering
The City utilizes two methods of vehicle detection for its traffic signals. An actuated traffic signal is one that will rest in green for a main street until it detects a vehicle on the side street or turn lane.
Most of the signals in Gahanna are at least partially actuated. The sensor the signal uses to detect a vehicle is either a loop of wire cut into the pavement that measures inductance triggered by the presence of metal within the loop area or a video feed from a fixed camera that uses the change in pixels in predetermined zones to indentify vehicle presence.
Many of the cameras you may see mounted at a traffic signal are monitoring vehicle presence within a given approach or lane. If video detection is being utilized at an intersection, there may be as little as one camera or as many as four depending on which directions require the presence of a vehicle for the signal to change.
In addition to the fixed video detection cameras, the City also has Pan-Tilt-Zoom (PTZ) cameras to monitor traffic on some of the major corridors throughout the City much like ODOT has on their freeway system. All of these cameras are pendent style mounts with a clear glass dome which protects the camera from the elements.
A listing of all the locations of our video detection cameras and PTZs can be found on our City maintained traffic signals map.
For more information about the City's Streets Division, visit them online by visiting http://www.gahanna.gov/departments/service/street.aspx
