EARTHWORKS ASSET ASSESSMENT USING REMOTE SENSING

The Highways Agency (HA) in the United Kingdom is responsible for managing 9,760 km of the motorway and trunk road network in England on behalf of the Department for Transport, (DfT). The most recent figures available indicate that the Highways Agency is spending upwards of 12m per annum on reactive slope repair and that year on year costs are increasing almost exponentially. This together with the requirement to increase capacity and reliability of the existing network have led the Highways Agency to institute a pro-active earthworks management strategy. One of the key requirements for the development of such a pro-active asset management strategy is the regular supply of current detailed asset inspection / condition data. Helicopter and fixed wing aircraft borne laser scanning (LiDAR) offers the opportunity of rapidly obtaining detailed digital ground survey data of large lengths of the highway asset, with the ability to survey some 100km of linear asset per day. The key product of the laser scanning is a detailed ground survey and this provides the potential for using advanced change detection techniques to digitally compare surveys and automatically identify areas of noteworthy earthworks deterioration. This would potentially allow more focussed ground inspections, with benefits in terms of speed and the reduction in exposure of staff to the hazards of working on live highways. With substantial areas of the network to review on a regular basis, an HA research programme has been initiated to evaluate the potential for LIDAR systems to identify condition features and the practicality of automated change detection. This paper describes the results from a trial on 20km of the M25 Motorway and outlines the potential for rapid population of earthworks asset condition databases using remote sensing techniques. Various operators of other infrastructure networks such as London Underground Limited, Railtrack Great Western Zone and the British Waterways Board have been closely involved with the research, recognising that similar techniques will have application in areas such as railways, flood defences, canals, dams, etc. For the covering abstract see ITRD E123761.