Catenary-Free Tramway Systems: Functional and Cost–Benefit Analysis for a Metropolitan Area

New tramway technologies such as “ground-level power supply systems” fit with the purpose of preserving historical heritage and urban environments of city centers. Such public transportation systems do not require a traditional air supply system (+ 750 V) and are therefore referred to as “catenary-free systems” (i.e., APS system, tramwave system, Primove system). Their implementation is becoming increasingly widespread, especially for cities with prestigious historical heritage, where high levels of environmental sustainability, capacity, reliability and safety standards are required. The study compares some of the most well-known and novel catenary-free systems for the creation of a 68-km tramway system, to be implemented in a metropolitan city. For each of the 7 new tramways, AIMSUN microsimulations were run to identify the most appropriate tramway track geometry and road section to minimize the interference with the vehicle activity. Moreover, for each system a financial and economic performance analysis has been carried out for an investment of about 869 million euros, while taking into account different scenarios of transportation demand. In addition, a cost–benefit analysis of the tramway lines investment project has been presented, including the calculation of the financial net present value, the economic net present value, rate of return of the investment and cost–benefit ratio. The analysis demonstrates that the APS ground-level power supply system is a proven alternative with greater economic and financial performance.