Data collection begins in January following the census year and continues for approximately 9 months. Reported data are for activity during the census calendar year. A stratified random sample of registered trucks is selected from all 50 states and the District of Columbia. Samples are selected by state and stratified mainly by body type. Data collection is staggered as state records become available.
Owners report data only for the vehicles selected.
Methods and limitations of the VIUS are described in the US summary and individual state reports published on the US Census Bureau web site. The United States release is also available in hard copy. A microdata CD-ROM, which is available about 26 months after the census year, contains unaggregated records for individual trucks by state. The records are masked to avoid possible disclosure of individual vehicles or owners. The Department of Transportation uses the data for analysis of cost allocation, safety issues, proposed investments in new roads and technology, and user fees.