California Partners for Advanced Transportation Technology

This report documents work performed under PATH Task Order 5314. The objective of this project has been to assess the potential benefits of a new loop detector card manufactured by Inductive Signal Technologies: the IST-222. The attractive features of this card include a) automatic detection of interference from nearby detectors, b) automatic sensitivity selection, c) high sample rates, d) real time noise attenuation, e) vehicle classification, and f) a USB port on the front panel. The evaluation was carried out in three phases: 1) a simple replacement of existing cards with new IST-222 cards, 2) an evaluation of PeMS' loop health diagnostic algorithm using the IST-222 USB port, 3) a field comparison of the IST-222 and the Rambo-222. As an extension to the scope of the project, we conducted a series of trials at the Richmond Field Station involving two traffic sensors: the IST blade sensor, and the Sensys magnetic sensor. Data and video were recorded for a range of speeds, offsets, and vehicle types.