CLASSAX is a new concept for automatic vehicle detection, classification (AVC) and traffic data collection combining the advantages of axle sensors with those of an inductive loop instead of considering both detection principles to be competing. A CLASSAX system is able yet not restricted to work with sensors which can all be installed flush with the roadway surface, thus being protected against various possibilities of being damaged and avoiding to produce noise. The detection zone is very well defined and can be made very short, which enhances reliability with slow traffic and is an essential requirement for true multi-lane capability. Moreover, all detection means required are available with static response, so the system is truly able to cope with traffic speeds down to zero.
Along with the philosopy of detection CLASSAX also comprises a new method for setting up classification schemes. Traditional AVC systems have a fixed behaviour which is difficult or even impossible to modify because they were designed from scratch for distinction of a pre-defined set of vehicle classes. In addition, definition of the particular classes' characteristics requires to have a large collection of vehicle data first, and both these data as well as the registration of the actual vehicle's according parameters must be very accurate. This adds considerable extra effort to the development so setting up custom AVC systems is very expensive.
With CLASSAX vehicle class characteristics are determined by a teach-in process utilizing real traffic; no initial inquiry of vehicle data is necessary. All parameters are measured the same way as in operation, thus any systematic errors are automatically taken into account and therefore cease to be errors in the original sense of the word. The customer can define any set of vehicle classes desired: if they are only indicated by different vehicle characteristics the system will identify them faithfully. The effort added to the system price by this teach-in process is negligible compared to what setting up a traditional custom AVC system requires.
Originally intended to be just an AVC system especially suitable for extremely slow moving traffic, CLASSAX can bring about much more than this. Being a bright example of a whole that is more than the sum of its parts it constitutes an instrument of outstanding versatility. Possible applications include vehicle detection, classification and counting, axle counting, traffic statistics, traffic monitoring and control, vehicle recognition and weigh-in-motion.