The risk of tripping accidents on public footways

Abstract

Highway authorities maintain footways in a safe condition following a regime of regular inspections, repairing hazardous defects found and resurfacing at less frequent intervals. The interval between inspections depends on the footway usage, and the reaction time for repairs depends on the hazard posed by the defect as well as the footway usage, reflecting the relative risk of an accident. Currently, these intervals are determined by judgement and this paper describes how the risk can be quantified. Records of third-party claims were examined for factors that influence numbers of accidents, including pedestrian age, defect size and footway construction. Statistics of accidents requiring hospital treatment and the results of medical research into walking provided further insight. By making a number of assumptions, a relationship between risk and defect height was derived. The cost to society of a footway accident was also determined. Thus, for a given footway network and maintenance regime, the likely number of accidents and their cost can be calculated. This enables highway authorities to compare the costs of different maintenance regimes with the benefits of accidents prevented. Collecting further data in a standard format would enable refinement of the model.