With the introduction of CA Traffic’s Black Cat radar sensor, I truly believe we have finally eliminated the need for road tubes! The following comparison study provides evidence to that end. For this study, I set up a pneumatic tube study concurrently with a Black Cat radar study. Here are the results:
Admirals Rd comparison study, Volume 
As you can see, the difference between the two technologies is about 1%; an excellent result! The Black Cats predecessor, the Jamar Radar Recorder, has been recognized for its accuracy, in volume studies. Please see; http://www.lrrb.org/pdf/2014RIC51B.pdf
However, for the Radar Recorder, percentage error was seen to be between 3% – 7%. My study indicates improved accuracy for the Black Cat recorder, to around 1%! However, volume accuracy has never really been an issue for radar.
In the past, accurate length measurement, has been radars greatest challenge. This is where the Black Cat is most improved. From the same Admirals Road study, I compared the classification tube results with the radar length results. I know this is comparing apples to oranges, as tubes measure axle length. Also, as the tubes use the FHWA F scheme, I needed to make some assumptions to group certain categories. The results are encouraging;
Admirals Rd comparison study, Class:
In the past, radars questionable length measurements have resulted in inflated truck percentages. That the percentage distribution for this study is very close is noteworthy.
