Road tunnels construction cost estimation: a structural equation model development and comparison

Sound understanding of technical projects performance is very important at the preliminary design phase. A crucial element in the decision-making process for selection of the best alternative solution is reliable, early cost estimates. This becomes particularly significant in road tunnel construction where the construction cost is expressively high and subject to considerable cost overruns due to inherit risks of underground conditions. In this paper a structural equation model (SEM) for estimating the final construction cost of road tunnels is developed. In a comparative analysis of SEM with multiple regression analysis (MRA) and neural networks (NNs), SEM offers better results allowing the user to visually depict the paths of how several variables affect the cost of an underground project.