There are two major sources for national reporting of transportation fatalities, most notably for highway fatalities—the U.S. Department of
Health and Human Services, Centers for Disease Control’s National Vital Statistics System (NVSS) and the U.S. Department of Transportation, National Highway Traffic Safety Administration’s Fatality Analysis Reporting System (FARS). Each data source has its own unique data collection and reporting criteria designed to fulfill the particular needs of the collecting agency. For example, the NVSS reported 35,400 highway fatalities and FARS reported over 32,700 highway fatalities in
2013 [USDHHS CDC VITALITY 2015].

The NVSS is based on death certificates recorded according to the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD–10) specifications and include not only fatalities that occurred on public roads, but off-road fatalities such as those attributed to
bulldozers on non-highway construction sites and harvesters on farms. FARS is based on police accident reports and mostly includes highway fatalities that occurred on public roads. Such differences in data collection, coding schemas, and reporting criteria lead to differing numbers.