Trends in driver and front-right passenger safety belt use in Michigan: 1984-1998.

As part of Michigan's effort to track trends in safety belt use within the state over time, the University of Michigan Transportation Research Institute conducted 20 statewide surveys of safety belt use between 1984 and 1998. Results indicate that Michigan safety belt use trends for drivers and front-right passengers are similar to other statewide and national trends. Belt use in Michigan increased dramatically immediately after the state implemented its mandatory belt use law (secondary enforcement) followed by a smaller decline that leveled off at a rate more than 20 percentage points higher than before the law. Belt use was consistently higher among drivers than front-right passengers, older than younger front-outboard occupants, females than males, and front-outboard occupants exiting freeways than those stopped at local intersections. Examination of belt use trends in Michigan provides useful information for continued efforts to increase belt use in our state and for all states interested in meeting national goals for safety belt use for the year 2000 and beyond.