The project involves the realisation of a mass rapid transit surface line linking the Northern Suburbs, Historic Centre and Southern Suburbs of the Municipality of Padua (the so-called SIR1; approx. length: 11 km). The main features of the project are: average distance between stops generally not less than 300-400m; average peak hour waiting time inferior to 6 minutes; 18 hours of daily operation (from 6 a.m. to midnight); max. capacity of 1,800 passengers/hour. The work was rendered particularly complex by conditions in the existing urban environment, by important interferences with daily life in the historical centre of Padua, and by the presence of numerous public utility lines, frequent traffic jams and night and Sunday shifts, the coordination of civil, electrical and mechanical works and temporary occupations of private property.