Long-term safety evaluation of the primary seat-belt law

• Published in: Journal of transportation safety & security 2022-10, Vol.14 (11), p.1976-1996
• Main Authors: Lee, Jaeyoung, Lian, Yanqi, Abdel-Aty, Mohamed, Mao, Suyi, Cai, Qing
• Format: Article
• Language: English
• Subjects: before-and-after study with the comparison group; crash modification factor; Enforcement; Fatalities; Long-term effects; Mortality; Passenger safety; primary seat-belt law; Seat belts; transportation policy
• ISSN: 1943-9962; 1943-9970
• DOI: 10.1080/19439962.2022.2033901

Many states in the United States have passed the primary enforcement seat-belt law. Though there is strong evidence from previous studies that enhanced seat-belt enforcement interventions can substantially increase seat-belt use, thereby reducing fatalities. It is still necessary to evaluate the long-term effects of implementing the primary seat-belt law. In this study, changes in fatalities over time after the primary seat-belt law enactment are investigated using before-and-after study with the comparison group methods for fatality modification factors (FMFs). This study confirms that the number of adult fatalities without seat-belt has significantly decreased by 17.29%. Another key finding is that the fatality rates in states with a higher maximum fine amount are significantly lower than those with a lower one, however, the decrease in fatality trend is not as effective above about $100 fine. Implementing the primary seat-belt law is significantly effective in reducing fatalities without seat-belt in the long-term. Meanwhile, the relationship between fatalities reduction and the maximum fine amount is not positively linear related. It is imperative that states with the secondary seat-belt laws must reform their seat-belt laws to the primary seat-belt law. An appropriate fine amount can be determined to maximize the effectiveness of the primary seat-belt law.