Polishing of road surfaces in New South Wales

An investigation into the cause and remedy of road slipperiness is described. Experiments were conducted on a number of aggregates of various geological types and a fair degree of correlation between road and laboratory artificial polishing established. Generally, a useful means has been developed of evaluating the skid resistance properties of aggregates for use in bituminous surface dressing work. Investigation has been extended to dense graded bituminous hot mixtures but the correlation between field and laboratory polishing was not good. Further study on this problem is required. A programme of future investigation is discussed (A).