Simulation and Field Verification of Vehicle-Loop Interactions

Inductive sensors are used worldwide for traffic control. These sensors consist of a loop or loops of wire embedded in the pavement. The loops are connected to electronic control circuits that convert changes in loop inductance to signals to control traffic lights or to monitor traffic. This work describes a simulation approach that permits reliable calculation of the response of loops of various geometries to various types of vehicles. The simulation models both the loop and the vehicles with a set of filaments of finite length. The simulation approach was validated using two different loop geometries and various types of vehicles. The simulation was developed to assist in the selection of a loop geometry for a particular application or to assess the likely behavior of hypothetical loops. As it is based on a fundamental description of the vehicle-loop interaction, the simulation approach is also expected to be useful in other investigations of loop responses.