The Crash Outcome Data Evaluation System (CODES) evolved from a congressional mandate to report on the benefits of safety belts and motorcycle helmets. The National Highway Traffic Safety Administration (NHTSA) has funded 30 states, though 3 states are currently inactive (Hawaii, Nevada, North Dakota), to link statewide crash and injury data. Tennessee has been an active participant in this project since 2001.
In 2004, Tennessee also became a NHTSA CODES Data Network State, now consisting of 21 states, allowing NHTSA to request Tennessee’s CODES linked/imputed data for nation-wide statistics and safety research. Tennessee’s CODES is funded by a federal grant managed by the Governor’s Highway Safety Office (GHSO). The GHSO's mission is to develop, execute and evaluate programs to reduce the number of fatalities, injuries and related economic losses resulting from traffic crashes on Tennessee's roadways. The office works in tandem with the National Highway Safety Administration.