With the greatest security we can affirm that the train continues to be a cheap means of transport within Italy. The railroads are from the State, although there are always some private lines. It has four types of trains, the Pendolino It is an interurban service, which are top notch. Then follow the Eurostar, this line manages to connect the main Italian cities with Barcelona, Hamburg, Vienna, etc. The Expresso, offers a range of long-distance trains, makes stops at almost all stations, finally there is the Direct, which only makes some intermediate stops on its route.
Rome, Milan, Naples and Genoa have metro service, it is definitely a fast and comfortable way in which you can move around the city, you will have the possibility to know tourist attractions because they make their stops there. You can buy tickets at the vending machines that are installed in the subway stations.
The Rail system It is first class, comfort does not compare to that of buses, which has excellent offers. The tickets are valid for 75 minutes in any combination of transport, you can take a bus, the tram and even more than one subway trip. You can buy them in coffee shops, kiosks and at the ticket offices of ATAC (bus and tram network) and COTRAL (meter network), make sure you take your ticket before getting into a vehicle.