The skid resistance of road surface is of paramount importance in enhancing road safety. The chance of occurrence of skidding is reduced with an increase of skid resistance.
At low traffic speed (i.e. 50km/hr), the skid resistance is mainly controlled by microtexture of bituminous aggregates. For road speed exceeding 50km/hr, the macrotexture of road surface comes into play which is
characterized by texture depth of pavement. Hence, surface texture becomes an important parameter when designing high speed roads and expressway. The typical texture depth for concrete carriageway is 0.7mm.
However, to maintain skid resistance provided by 0.7mm texture depth of concrete carriageway, 1.5mm texture depth is required for bituminous pavement in high speed road.
This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.
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