This Report describes a survey and analysis of the defects found using closed circuit television (CCTV), of about 5 km of highway drains in each of four areas - Avon, West Midlands, Lancashire and Yorkshire. Overall 9.3 per cent of the pipes inspected were structurally damaged while large-displaced and open joints were found on 5.3 per cent. The relation between these defects and the age of construction, depth to invert, soil type and location are examined. Nearly a third of connections were found to be faulty and it is concluded that their substitution by junctions would remove an obvious source of defects. Other findings are that the incidence of structural defects were considerably lower on motorway and trunk roads than on other types of road, that present design methods were probably adequate but the supervision of construction could be improved, that the defect classification and survey methods used for sewers could be applied to highway drains and CCTV surveying of newly constructed highway drains is recommended PRIOR to the end of the contract maintenance period.

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