A Comparison of One-Pass and Bi-directional Approaches Applied to Large-Scale Road Inspection

Gaist Solutions Ltd. carries out national-scale road inspection surveys in the UK. Visual inspection is used to identify the need for road maintenance. An inspection vehicle that monitors one side of the road needs two traversals to monitor a typical road, whereas a vehicle with cameras that record both sides of the road only requires a one-pass approach. To determine whether the one-pass approach affords any real cost advantage, we analyse road networks of six typical UK cities and the county of Norfolk using a range of exact and heuristic methods, and extrapolate from our results to estimate the cost-effectiveness of these two approaches for the road network of the UK. Our analysis approach is based on the Chinese Postman Problem (CPP), using graph reduction to allow effective computation over very large data sets.