A life cycle model for estimating road tunnel cost

The estimation of road tunnel costs is crucial for motorway operators and transport infrastructure project managers. This paper presents a life cycle model for estimating costs in road tunnels. The research is based on a data set of 32 dual bore road tunnels, with a total length of 55 km, which are part of the Egnatia Odos Motorway in Northern Greece. The factors affecting civil engineering construction works and electromechanical installations are analyzed in great detail. Energy consumption and operation and maintenance costs are examined. Additionally, replacement costs are studied for an operation period of 75 years. Overall, Artificial Neural Networks are employed to estimate final costs in relation to tunnel design input parameters. The life cycle cost model uses depreciation and price escalation on all costs. It is concluded that the proposed framework can assist tunnel operators and asset managers in reliable costing of alternatives as well as developing operation and maintenance strategies.