Effect of reducing urban road speed limits on motorcyclist traffic accidents: a before-and-after study using the National Emergency Department Information System of South Korea.

BACKGROUND

Motorcycles are widely used in various transportation sectors, but riders are directly exposed to external risks. Consequently, motorcyclists are more vulnerable to severe injuries. Road speed limits serve as key policy interventions to mitigate this risk. This study aims to evaluate the effects of reducing urban road speed limits on motorcyclist traffic accidents.

METHODS

In this study, National Emergency Department Information System data from the seven largest cities in South Korea were analyzed by comparing a pre-implementation (April 17, 2018 to April 16, 2019) and post-implementation (April 17, 2021 to April 16, 2022) phase. The Pearson chi-square test was used. Additionally, univariable and multivariable logistic regression analyses were performed to assess the effects of the policy on emergency operations, intensive care unit (ICU) admission, and clinical outcomes. Statistical significance was set at p<0.05.

RESULTS

The number of patients decreased from 16,124 to 13,201, along with a reduction in emergency surgeries (n=61) and ICU admissions (n=184); however, unfavorable outcomes increased (n=9). The risk of emergency surgery (adjusted odds ratio [aOR], 1.093; 95% confidence interval [CI], 0.935-1.277) was not statistically significant. However, the risk of ICU admission (aOR, 1.147; 95% CI, 1.015-1.296) and unfavorable outcomes (aOR, 1.502; 95% CI, 1.052-2.145) increased significantly in the post-implementation period.

CONCLUSION

Although the number of patients significantly decreased, there was no corresponding improvement in clinical outcomes. Instead of abolishing the policy, revising it would be a more appropriate approach. Therefore, additional public interventions and educational programs are required.