Comparison of Preliminary, Initial, and Final Construction Costs of Italian High-Speed Railways

The planning of high-speed railways (HSRs) in any megaproject faces challenges in providing reliable forecasts about financial aspects. This study presents the condition of Italian HSRs by focusing on the lines built or under construction in the last 30 years. The primary technical characteristics are illustrated for each, together with an analysis of the preliminary, initial, and final costs (when the line is completed). Our research reveals an interesting aspect: the final costs are always higher than the preliminary costs, with the cost variation presenting peaks of more than 360% and an average value of 165%. However, except for Turin–Milan HSR, they are often lower than the funds available at the beginning of construction work. Hence, Italian HSRs seem to demonstrate a specific capacity for project management and tendering processes to correctly estimate costs and timing. Meanwhile, Italian HSRs’ unitary costs are generally higher than the European Union average, an aspect that is only partially explainable by Italy’s geomorphological specificities, which might hide some marginal buffer that could be included in the initial phase of project construction.