Estimated Safety Belt Use Rates Under Primary and Secondary Enforcement Statutes

Book excerpt: The Virginia Transportation Research Council was requested by the Virginia Department of Motor Vehicles to estimate the changes in statewide safety belt use that would occur if the state were to modify its current mandatory use law (HUL) to permit primary enforcement. In carrying out the project, a literature review and a review of all state HUL statutes were conducted. In addition, three sources of data (two national and one state) were used to identify whether there were variations in the rates of safety belt use and the factors influencing any differences found. Several factors relevant to safety belt use were identified. Thirty-seven states and the District of Columbia have an MUL, and 9 provide for primary enforcement. It was found that belt use was generally greater in states with primary enforcement. In addition, belt use was higher in localities with both an active public information campaign and an active enforcement effort. Finally, there was a large increase in belt use by front seat occupants in Virginia after passage of the HUL, whereas belt use by rear seat occupants dropped dramatically during the same period. It was concluded that either of two actions would result in a 6 to 8 percentage point Increase in the statewide belt use rate. These two actions are (1) modify the current MUL to provide for primary enforcement, or (2) amend the current HUL to apply to both front and rear seat occupants. Either change would result in a rise to a rate of approximately 62% from the current rate of 54%.