This paper gives an overview of the dual effects of the opening, in Italy, of the new HSR line with a single operator (between 2005-2012) and the effects of a new operator entering the HSR market (2012-onward), on supply, demand and prices, thus inferring the effects of competition in this typically monopolistic market. The analyses are based on source data (laws and regulations, business plans, timetables, prices) as well as ad hoc extensive surveys, such as on-board counts on the HSR and intercity trains, retrospect surveys, and RP/SP interviews. In addition, an integrated modeling system has been developed to forecast the effects of competing titnetables/services/prices in terms of different HSR operators, competing modes (air/auto/railw...