In an effort to compare sensor technologies, Tim Erickson (360-705-7343) of WSDOT sponsored a test to compare the accuracy of a quartz sensor based WIM system with an IRD weighbridge based WIM system. The quartz sensors were installed in the same lane about 150' downstream of the weighbridge according to Mr. Erickson, and the results were compared to the static weight which was determined on the enforcement scale at this location.


A sample of the results compiled by WSDOT is shown below: