Seat belt use in Washington State, 2015 : as submitted to the National Highway Traffic Safety Administration per 23 CFR Part 1340: Uniform Criteria for State Observational Surveys of Seat Belt Use.

Seat belts are highly effective for reducing the severity of traffic injuries. Seat belt use by all motor vehicle occupants is both a national and Washington State priority. Over the past three decades, dramatic increases in seat belt use have been achieved through the enactment of mandatory use laws, law enforcement strategies, and public education campaigns. Washington enacted a secondary enforcement seat belt law in 1986, and since then annual observation surveys of belt use have been conducted in order to assess changes in the rates of belt use in Washington. Until 2013, the Washington Traffic Safety Commission (WTSC) had conducted all annual seat belt use surveys according to a methodology designed by WESTAT, Inc., which reflected the state’s population and vehicle-travel patterns present in 1986. In 2010 the National Highway Traffic Safety Administration (NHTSA) proposed changes to 23 CFR Part 1340, the federal statute outlining the requirements under which all states are meant to conduct their seat belt surveys. This proposal called for a nationwide upgrade and update of survey methodologies across the states. After a public comment period on the proposal, NHTSA published a Final Rule on April 1, 2011, including detailed responses to public comments generated by the Proposed Rule. Accordingly, through a competitive-bid process the WTSC selected and contracted with a private vendor, Resource Systems Group, Inc. (RSG), based in White River Junction, VT, to design Washington’s new survey methodology according to NHTSA’s specifications. In early 2013, NHTSA accepted Washington’s proposal for the new seat belt observation method developed by RSG. The new method resulted in an entirely new selection of survey observation sites and a more comprehensive survey weighting approach. The result of this new methodology was a slight decline in the statewide seatbelt use rate estimate (from 96.9 percent in 2012 to 94.5 percent in 2013). This decline did not represent a decrease in statewide seatbelt use but rather is due to the change in methodology. Due to the change in method, seat belt use estimates derived under the new method (2013 and forward) are not comparable to estimates derived under the old method (2012 and previous). The new methodology results in a more accurate estimate with greater confidence. The statistical level of accuracy with the new methodology is nearly double what it was under the old methodology. The remainder of this report will describe the results of the 2015 seat belt survey’s results. (Author/publisher)