Speed Measurement with Inductance Loop Speed Traps

摘要

The research effort evaluated the use of inductance loop detectors in a freewaymanagement situation to determine optimal speed trap distance, best wire type, shortest response time condition, and most accurate speed detection scenario. Five speed trap distances were evaluated with a variety of detector units. An optimal speed trap distance was not identifiable. However, the research consistently identified that the best method for obtaining accurate speeds requires the use of inductance loop detectors utilizing identical make and model detector units. The researchers also compared single conductor wire and multiconductor cable inductance loops for accuracy of speed measurement. It was found that the response times for multiconductor cable inductance loops are significantly shorter and more uniform than response times using loops formed with single conductor wire.