M.R. Ahadi - Assistant Professor, Road Safety Dept., Transportation Research Institute, Iran University of Science & Technology (IUST), Tehran, Iran
K. Nasirahmadi - M.Sc., Graduate, Highways & Transportation, Tehran, Iran

Skid resistance and road condition are common indices of road safety; therefore providing adequate skidding resistance will reduce the incidence of road accidents. The surface macrotexture has a large effect on the characteristics of road surface skidding, which is the focus of this research. During the study, the mean texture depth of the road surface was measured, in order to determine the conditions that ensure the maximum contact area between the vehicle tires and road surface during wet conditions. The Pavement Guideline No. ۲۳۴ was consulted for the test procedure and road surface composition, which used open and dense graded crushed lime aggregates with varying percentages of bitumen applied to the mix design. The samples were then tested to assess their stability using the Marshall and Gyratory Tests. The results showed that with the application and evaluation of the sand patch method, where the effect of the macrotexture on skidding resistance was analyzed with various gradations, there was an improved higher skidding resistance and a subsequent projected reduction of accidents with an increased safety.

Safety, Skid Resistance, Micro & Macro Texture, Sand Patch, British Pendulum Tester