Advanced Control Technology in Urban Traffic Control Systems. Volume IV. Vehicle Detector Tests

摘要

In the past, inductive loop detectors were used principally for indicating and counting vehicle 'presence'. Since 'presence' was most commonly used only with semi-actuated controllers there was little need for accurate knowledge of how long the vehicle was in the loop. However newer computer controlled traffic systems make use of this quantity, for example, to derive occupancy and average speed. Thus, the space and time error characteristics of the detector which affect these quantities are of greater importance. This volume describes an investigation into the accuracy properties of the fixed frequency variety of inductive loop detectors and summarizes the resulting data. (Author)