Taking a public coach or intercity bus to Rome
The price is about the same, but bus trips are longer and less comfortable—plus they have to deal with Rome's chatoic traffic, making that last (or first) leg of the journey in or out of the city sometimes interminably long.
However, buses can be handy (but crowded) when the rail system goes on sciopero (on strike)—not as common as in the 1980s and 90s, but it still happens a few times a year.
Every major European coach line and most regional Italian bus companies all have lines to Rome; you can get details on connections with cities across Ialy and Europe at the websites listed under "Details," below.
Many intercity buses arrive on or near Largo Guido Mazzoni by the secondary Tiburtina train sation—though some also have a depot on or near Piazza Cinquecento outside Stazione Termini (the main rail station). Many also have suburban bus stations as well.