UMTRI Project

Nighttime Safety Belt Use Survey

Sponsor: National Highway Traffic Safety Administration
Investigator: David W. Eby
08/25/2005 - 01/24/2007

The safety belt is the single most effective system for reducing the severity of injuries during a motor vehicle crash. They are only effective, however, if they are used consistently. The United States (US) has made great strides in increasing use of safety belts, with nationwide belt use around 80 percent. However, nearly all direct observation studies of safety belt use are conducted during daylight hours. Recent research suggests that nighttime safety belt use may be lower than use rates during the day.

Analysis of Fatality Analysis Reporting System data shows that safety belt use among fatally-injured-front-seat passengers is less than 35 percent between the hours of 10:00 PM and 5:00 AM, whereas belt use among fatality-injured passengers between 8:00 AM and 5:00 PM is about 20 percentage points higher. A recent direct observation study of nighttime versus daytime belt use in Connecticut, utilizing night-vision technology, found that belt use during the day was 83.0 percent while belt use at night was significantly lower at 76.6 percent use. This study also measured daytime and nighttime belt use before and after Connecticut’s May 2004 safety belt mobilization campaign. The study found that belt use increased during the daytime and nighttime, but the nighttime belt use increased by a significantly greater number of percentage points. Thus, this study suggested that the mobilization campaign was effective during both the daytime and nighttime, but nighttime belt use was still less frequent than during the daytime.

The proposed study has two objectives: 1) Determine if the pattern of higher belt use during the day found in the previously described studies is also found outside the Northeast region of the US; 2) Determine if there is a differential change in daytime versus nighttime safety belt use observed immediately following the May 2006 national safety belt mobilization campaign.