Large Truck Travel Estimates from the National Truck Trip Information Survey

摘要

The report describes the methodology of the National Truck Trip InformationSurvey (NTTIS) conducted by the Center for National Truck Statistics of the University of Michigan Transportation Research Institute. The survey was conducted to achieve the two main goals of estimating the registered large truck population of the continental United States and providing detailed data on their annual mileage. Travel in the file can be cross-classified by road type, area type, and time of day and broken down according to truck configuration, cargo type and weight, cargo body style, and driver characteristics. The report compares national population estimates from the NTTIS file with estimates from the Truck Inventory and Use Survey and with annual figures published by the Federal Highway Administration. In general, the agreement between NTTIS and TIUS was found to be good. The different years in which the surveys were carried out and differences in methodology probably account for the minor discrepancies that were noted. On the other hand, FHWA estimates of both vehicle counts and total mileage were found to be substantially higher than the NTTIS and TIUS estimates. It is likely that data submitted by the states to FHWA contain inaccuracies that result in inflated estimates.