The initial collection of Motor Carrier Census Data occurs when a carrier secures a USDOT number from the U.S. Department of Transportation. This data gathering primarily involves two forms: the MCS-150, which is completed by the carrier themselves, and the MCS-151, which is filled out by law enforcement during investigations. It's mandatory for carriers to refresh their MCS-150 data every two years.
In states that participate in the Performance and Registration Information Systems Management (PRISM) Program, carriers update their census information as they go through the Commercial Motor Vehicle (CMV) registration process. This census information is utilized by the Commercial Safety Measurement System (CSMS) for the purpose of identifying carriers and standardizing safety-related data. Census data encompasses a variety of information such as the carrier's USDOT number, official name, quantity and type of Power Units (PUs), vehicle miles traveled on an annual basis, physical address, operational status, and the kinds of cargo transported.