Analysis of the Safety Performance of Drainage Pavement focusing on Pavement Age

Abstract

This study analyzes the relationship between accident risk and the age of drainage pavement also known as porous asphalt. The analysis is based onempirical data from an urban expressway in Japan. Drainage pavement has been the most common type of road pavement in urban expressways due toits permeability function, which provides a safer driving environment in wet weather.However, thisfunctiondecreases over time, andtimely maintenance is necessary to ensure road safety. It is therefore essential to understand thechange in the safety performance over the service life of drainage pavements. This study defines safety performance as the number of accidents per unit of vehiclekilometer traveled, considering factors such as pavement age, weather, and road geometry. Statistical analysis based on the Poisson regression model revealed that, under wet condition, pavement age has a positive effect on accident risk mainly on curve segments.