Statewide Monitoring of Truck TrufficUsingAutomatic Vehicle Classifiers

In the past. collection of vehicle classification (VC) data was difficult and costly. Such data often had to be collected manually. Recently, considerable advances have been made concerning automatic vehicle-classifier (AVC) technology. AVCS are devices capable of providing a record of vehicle volume with respect to vehicle type. Most highway agencies in North America now employ permanent automatic vehicle classifiers (PAVC) at some locations on their networks. In addition, there is a considerable interest on the part of these agencies to expand their existing PAVC programs and use available portable AVC technology to undertake seasonal and short-period vehicle classification counts. While AVC technology has advanced considerably in the past few years, the practices of collection, analysis and application of AVC data have not progressed similarly. The main objectives of this study are 1) to demonstrate the need for an accurate truck volume and classification data in overlay designs of pavement: 2) to study temporal and spatial variations in vehicle composition and truck volume at a number of PAVC sites located in the Canadian provinces of Alberta and Saskatchewan; and 3) to study errors associated with sample estimates of truck annual average daily traffic (TAADT) and vehicle classification.