Can Non-Monetary Sanctions Improve Road Safety? A Policy Impact Assessment of Thailand’s Demerit Point System

Thailand's road accident rate ranks among the highest globally, causing significant harm to individuals and economic losses. In 2023, the government introduced a demerit point system—a policy with mixed international outcomes. This study evaluates its impact on daily accident rates in Bangkok, analyzing data for all vehicle types, private/public passenger vehicles, and motorcycles. Using interrupted time series analysis, the results show that while the demerit point system did not reverse the upward accident trend, it effectively moderated the rate of increase. Behavioral economic concepts such as present bias, status quo bias, and loss aversion offer additional explanations for the observed behavioral patterns. Statistically significant variables affecting accident frequency include weather conditions and temporal factors such as weekends and festival holidays. These findings suggest that enhancing the system’s effectiveness could involve strategic measures such as increased point deductions during high-risk periods like festivals, along with communication campaigns that emphasize loss-framed messages to discourage risky driving behavior.