A task-based safety model for construction projects

Construction remains one of the most dangerous occupations in the United States according to labour statistics. In recent years, the opportunity to accelerate the integration of design and construction activities has risen to allow maximum accident reduction while minimising adverse impact on project cost and schedule. This paper introduces a novel safety model formulated upon the statistical relationship between construction trades and their corresponding occupational risks. In the model, a project is broken down into a group of construction tasks for which the potential risk of accidents is estimated based on trade classifications of performing workers, historical accident rates and durations of exposure. When aggregated, these results reflect the estimated level of safety risk for a specific project as derived explicitly from its physical features. The estimate is further refined by incorporating non-physical features such as contract type, contractor’s experience, risk-sharing mechanism and site conditions. This model can be applied not only to produce an initial hazard assessment useful to safety professionals but also to allow architects and contractors to evaluate different design options for risk-mitigation purposes.