The Effect of Pollutants, Dust and Dune Sand Covered Over the Surface of Asphalt Pavements on Road Safety (Case Study, Sistan and Blouchestan Province, Iran)

Envirnmental factors such as seasonal winds, together with pollutants, dust and dune sand, reduce the drivers’ visibility, and when settled over the road surfaceproduce a negative impact on the skid resistance of asphalt pavements. In this study, the effect of dust and dune sand on the surface macro texture of road asphalt pavements in several sites, located in the Sistan and Balouchestan Province in Iran, was investigated. For this purpose, five road sections located in the areas with long periods of intense dusty and sandy winds , were monitored over a period of one and half months. In each site, the road surface under consideration was initially cleaned. Then, throughout the monitoring process, the images from these road surfaces were digitally taken and processed using an image processing software. Thereby, the road surface brightness parameter was calculated. Moreover, the macro texture depth of road surface in each site was also measured. The results indicated that there is an adverse relationship with strong correlation between the surface contaminations or brightness with the mean macro texture depth of road surface. The results also indicated that the rate of reduction in the mean road surface texture depth and brightness would reduce with time.