Connecticut Nighttime Safety Belt Use:
Observed and FARS Analyses

Safety belt use in the United States has risen steadily over recent years (Glassbrenner, 2003). The National safety belt use rate in 2004 was 80 percent; a 5-percentage-point increase over the 75 percent use rate in 2002. Yet, using the National Highway Traffic Safety Administration (NHTSA) Fatality Analysis Reporting System (FARS), safety belt use among fatally injured front-seat outboard occupants of passenger vehicles was only between 42 and 46 percent for the years 1999 to 2003.

One possible explanation for this discrepancy is that drivers most at risk of serious crashes also tend to be those who use their safety belts less often. For example, Hunter et al. (1993) showed that drivers who were unbelted had more than a third more crashes and more than two-thirds more convictions. Thus, it is likely that there is a subclass of individuals who less frequently use their belts and are more likely to crash.

Another possibility has to do with safety belt use during different times of the day. Reported safety belt use rates are in fact daytime belt use rates. Observations of belt use occur exclusively during the daylight hours and therefore exclude safety belt use rates at night. There exists the possibility that nighttime belt use is significantly lower than daytime belt use. It has been shown that there is a much higher per mile crash rate at night. Thus, if there is a lower belt use rate at night, then this lower rate would be associated with a disproportionate number of deaths and injuries. It is possible that the lives saved by safety belt use during the day are somewhat offset by lower belt use at night.

According to FARS data from NHTSA’s National Center for Statistics and Analysis, nighttime occupant fatalities rose from 14,048 in 1998 to 15,657 in 2002. Daytime fatalities remained roughly constant over this time span: 15,530 in 1998 and 15,401 in 2002. While the reasons for this discrepancy are not precisely known, this unfortunate trend bears mentioning as part of the broader context of emerging efforts to increase belt use at night.

One study supports the fact that high-risk drivers fail to buckle up more at night. Noordzij et al. (1988) reported that young drivers and drinking drivers in the Netherlands were less likely to be restrained during the night. At the time of the study, young drinking drivers buckled up only 21 percent of the time.

Wells et al. (1992) conducted a study looking at the effects of a combination DUI/safety belt enforcement program on driver blood alcohol concentration and safety belt use in Binghamton, New York. Belt use was observed during the day (2 p.m. to 4 p.m.) and at night (9 p.m. to 2:30 a.m.). Safety belt use prior to enforcement during the day was 46 percent. Safety belt use at night (prior to enforcement) was 11 percentage points lower at 35 percent.

Another study also showed differential belt use by time of day. Preusser et al. (1993) conducted a study in New York where safety belt use was observed for bar patrons leaving bars at night (9 p.m. to 2 a.m.), a control group driving through intersections near the bar at night, and drivers traveling through the same intersections during the day. The study demonstrated that belt use was 7 percentage points lower during the night than day. Bar patrons at night were restrained 18 percentage points less often than day drivers were. Non-bar-patron belt use steadily dropped as night approached and was lowest between 1 a.m. and 2 a.m.

The Preusser et al. study was conducted at well-lighted intersections and bar parking lots. Many highways are unlighted for many miles at a time, and rural roadways are also frequently unlit. The approach of conducting all observations in lighted areas is not only impractical (especially for nonurban areas) but could seriously bias any overall statewide results. Newly available night vision equipment, which better offsets the glare of vehicle headlights, and other special equipment may serve as a solution by allowing the observation sites to be selected regardless of the extent of overhead lighting.

Connecticut conducts a full daytime belt use survey each year in compliance with the Uniform Criteria for State Observational Surveys of Safety Belt Use conducted in connection with Section 157 of Title 23, United States Code (also known as “S. 157 compliant,” or a NHTSA-approved observation plan for determining statewide belt use). In June 2004, a full statewide nighttime belt use survey using night vision equipment was conducted simultaneously to the full statewide daytime survey. The day-versus-night observations were nearly identical with respect to observation procedures and location. They differed primarily with respect to time of day. Additionally, analyses using FARS were conducted to explore belt use rates among the fatally injured during different times of the day.

The results of this paper begin with a discussion of night-versus-day belt use nationally, based on belt use among fatally injured occupants from FARS. There will then be a discussion regarding observed safety belt use in Connecticut. Last, there will be some analyses pertaining to Connecticut safety belt use during the day and night before and after the 2004 Click It or Ticket traffic enforcement program.