How is the data collected and processed?
Data is collected from devices called loop detectors that are buried in the pavement on each approach to a signalized intersection. These loop detectors are located about 100 feet back from the intersection. We collect data that measures the percentage of time that a vehicle is located over the loop detector. This measurement is called occupancy. We then use the occupancy value and information on the number of lanes to estimate the congestion level on the roadway segment approaching the signalized intersection. For purposes of the map, a roadway segment is the segment of roadway between two the nearest signalized intersections.
