Road traffic accident is a major problem for the economy and society of ASEAN countries. In each year, road traffic accidents in Thailand cost millions of baht and inflict a large loss of life. Many of these accidents arecaused by environmental or road conditions. Poor visibility on wet pavement is one cause of accidents. Accumulated water on wet pavement surfaces can create the splash and spray effect, resulting in visibility loss. The main objective of this study is to develop simple methods for measuring and comparing visibility loss between conventional dense-graded, Stone Mastic Asphalt (SMA), and Porous Asphalt (PA) pavements. Light Reduction Method (LRM) and Color Changing Method (CCM) were found to be the appropriatetests for visibility loss measurement. The test results from both LRM andCCM show that the visibility loss is significantly greater for conventional dense-graded pavement when comparing to SMA and PA pavements. It was found that the amount of water level, speed, and vehicle size significantlyaffect the visibility loss due to splash and spray. The models for predicting the percent of visibility loss was also developed and could be useful for the selection of pavement surface to reduce splash and spray under wet pavement conditions, and thus to improve road safety.
Abstract