a working party was set up under the auspices of the department of the environment, the county surveyors' society and the asphalt and coated macadam association to determine the causes of failure of a number of rolled asphalt wearing courses by sliding relative to the basecourse; failures normally occurred shortly after the completion of the construction of new roads. most of these failures were reported in the eastern part of the country from nottinghamshire northwards as far as aberdeen in scotland. the report gives an analysis of the factors stated to be present in the 56 failures discussed; most failures are associated with wet-mix or dry bound macadam bases laid in winter and early spring, but many counties using wet-mix bases have reported no failures. an appendix shows the extent to which wet-mix road bases were used during the period 1970-74. recommendations are made about the use of wet-mix and dry bound macadam bases, and the manufacture and laying of rolled asphalt wearing courses. recommendations are made about further investigations needed, including the possible relevance to failure of the structural condition of the road when the surfacing is laid, of the properties of the binder in relation to the laying conditions and of the importance of adhesion between wearing courses and basecourses. the county surveyors' society was not able to agree with the main conclusions of the report, and a rider to this effect has been added. (a)

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