Inductive loop vehicle detectors currently used to control traffic signals have proved inadequate for the detection of bicycles. The report describes tests which show that the `Symmetripole' inductive loop design currently being installed is very dependent on the bicycle's position in the lane. Three different loops which had been described in literature as being designed specifically to provide improved detection of bicycles were trialled against the Symmetripole. All four loops were installed along a section of test pavement. The experiment consisted of a cyclist riding over the loops along each one of eight lines in turn. The loops were connected to a standard inductive loop vehicle detector circuit with variable sensitivity. The loops' sensitivity to three different bicycle types across the width of the lane was thus measured. The results show that an inductive loop design used to detect bicycles in Beijing, China, exhibits a good response to all bicycle types tested while being of simple design and consequently simple to install. (A)
Abstract