USING WEIGH-IN-MOTION DATA TO CALIBRATE TRADE DERIVED ESTIMATES OF NAFTA TRUCK VOLUMES IN TEXAS

Weigh-in-motion (WIM) sites are being installed along many highway corridors that carry international trade trucks. Estimating the numbers of trucks carrying international commodities currently relies on manipulating trade databases, making some adjustment for empty vehicles. The variety of vehicle classification data measured at WIM sites provides a rich source of data to enhance this adjustment process. Previous WIM border data has focused on port of entry traffic heavily influenced by drayage operations. This paper examines how WIM data collected on truck corridors can be used in the determination of standardized truck volumes (termed equivalent trade trucks or ETT) on international highway corridors. Data from the Texas-Mexico border are used to determine ETT NAFTA volume