Effects of road geometric parameters on safety: A case study of Mugling-Narayanghat road in Nepal

Road safety has emerged as a global priority due to the multifaceted consequences of road traffic accidents (RTAs) in modern society. The study is focused on the development of an accident prediction model (APM) and identifying the influence of geometric factors on road safety. The study section of the highway was divided into 190 identical segments based on geometric characteristics. Eight models have been developed for establishing the relationship between crash numbers and respective parameters. The significance of the models has been validated by the Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC). The study unveils that the shoulder and lane width, numbers, and radius of the horizontal curve significantly influence RTAs. However, the gradient and shoulder type have less impact on road accident frequency. The research recommendations for the improvement of safety are increasing the radius of the curves, lane, and shoulder width. Similarly, the study suggests the reduction of the number of horizontal curves for the reduction of crash frequency.