Increasing seat belt use in the United States by promoting and requiring more effective seat belt reminder systems

Federal Motor Vehicle Safety Standard (FMVSS) 208 requires every passenger vehicle to provide an auditory signal lasting 4 to 8 seconds and a visual display lasting 60 seconds when the driver is unbelted at ignition. This requirement does not increase seat belt use. This paper summarizes the latest research on using vehicle technology to increase seat belt use and existing safety standards worldwide to support the strengthening of FMVSS 208.

Studies of seat belt reminders and interlocks published in peer-reviewed journals, conference proceedings, or as technical reports were identified in online databases and reviewed along with current requirements worldwide. Results from past research were used to estimate the front- and rear-seat daytime belt use rate and the annual number of lives that could be saved by a persistent audible reminder at each seating position.

Most motor vehicle occupants routinely buckle up. Those that do not typically forget, are going a short distance, or find belts uncomfortable. Seat belt reminders can remind or motivate occupants to buckle up. Enhanced reminders that exceed FMVSS 208 increase belt use by 6 percentage points. Reminders also can increase rear belt use, and although required throughout the world, are not required by FMVSS 208. More persistent reminders, like those required around the world, with a continuous, long-lasting audible signal increase belt use by 30% among drivers who do not routinely buckle up. If every vehicle in the U.S. had such a reminder at each seating position, then it was estimated that the daytime belt use rate in the U.S. would increase about 3 percentage points from 90.3% to 93.2% in the front row and by about 6 percentage points from 80% to 85.9% in the rear row. It was estimated that the increase in belt use from a continuous, long-lasting audible reminder could potentially save about 1,600 lives each year.Seat belt interlocks can increase belt use, but acceptance is a stumbling block. Public outcry ensued after interlocks were required in 1973, and public sentiment remains negative. Opinions toward front and rear reminders are more favorable. Furthermore, past research suggests interlocks may be no more effective for increasing seat belt use than persistent audible reminders. The effect of interlocks on rear belt use have not been explored.

Persistent seat belt reminder systems that last at least 90 seconds can potentially save hundreds of U.S. motorists each year. Robust empirical evidence, successful exemplars from organizations throughout the world, and a clear public health benefit exists for strengthening FMVSS 208 to require more persistent audible reminders at every seating position.