Evaluation of the possibilities to use commercially available vehicle detectors for speed and occupancy measurements

There is some doubt about the correctness of the speed measurements made with two short loops and two standard detectors. This report defines a list of requirements for the detector based on the evaluation of the various detectors and rebalancing systems. A few remarks on occupancy measurements have been included. It gives an overview of the performance of the detectors with respect to the following criteria: first stage transferfunction, disturbances in the first stage, trigger level, off-on and on-off delay, time-out, temperature shock, humidity, and power and output. This is followed by the conclusions for each detector separately combined with some short remarks on the specific detector.