NASS-CDS: Sample Design and Weights

The National Automotive Sampling System (NASS) is a nationwide motor vehicle crash data collection program operated by the National Center for Statistics and Analysis (NCSA) at the National Highway Traffic Safety Administration. The purpose of NASS is to produce statistics on national motor vehicle crashes and to provide a database for the development and the evaluation of motor vehicle and highway safety standards. See Web page www.nhtsa.gov/NASS for an overview of NASS. NASS consists of two subsystems: the General Estimates System (GES) and the Crashworthiness Data System (CDS) – both probability sample surveys of police-reported motor vehicle traffic crashes across the country providing national estimates on crash, vehicle, and occupant characteristics. The purpose of this document is to explain how CDS weights are developed from its sample design. Section II is about CDS target population, section III gives a description of CDS sample design, and section IV discusses the weight calculation procedure in CDS.