An experimental instrumentation system for monitoring long lengths of traffic railings to detect encroaching vehicles and measuring impact condition has been developed and subjected to preliminary evaluation. The system makes use of the traffic railing as part of a transmission line carrying two radiofrequency waves. The radiofrequency energy reflected from vehicles entering the electromagnetic field about the line is detected and used to determine vehicular speed, direction, angle, location, path and size. A solid-state, digital data acquisition system is triggered by a detected encroachment to record pertinent data. Capability to record data on up to 50 encroachments is available. Computer data processing generates plots of vehicle path and tabulates data on time, speed, angle, location of encroachment, vehicle size and nature of encroachment.
Abstract