Buy a ticket before you get on the bus or tram. Tickets can be purchased in metro stations and tobacco shops and are not available on board buses or trams.
Be sure to validate your ticket as soon as you get on board. Your ticket is good for 75 minutes and one metro ride from the time its validated. Ticket inspectors frequently board buses and trams, and an unvalidated or expired ticket will garner a steep fine, starting at 50 euros.
Expect variability in schedules. The metro and trams run mostly on time, but buses can be highly irregular. It is possible to wait 25 minutes or more for a bus, and then have two or three arrive at the same time.
Save your feet from Rome’s hard cobblestones by making use of the bus. While not always efficient, buses cover far more of the city than the metro or trams.
Look out the windows. This is a great way to orient yourself with the city, and it’s the cheapest tour you’ll find. Glide past ancient ruins and chic stores, and take advantage of the outstanding people watching.
Be aware of when a bus, tram, or train makes its last run. It tends to be substantially earlier than when transportation stops in a comparable American city. Holidays and city events can also alter schedules, often without warning.