Although most of Rome's sights are in a relatively circumscribed area, the city is too large to be seen solely on foot. Try to avoid rush hours when taking the Metro (subway) or a bus, as public transport can be extremely crowded. Midmorning or the middle of the day up until early afternoon tends to be less busy. Otherwise, it's best to take a taxi to the area you plan to visit if it is across town. You should always expect to do a lot of walking in Rome (especially considering how little ground the subway actually covers) and so plan on wearing a pair of comfortable, sturdy shoes to cushion the impact of the sampietrini (cobblestones). Get away from the noise and polluted air of heavily trafficked streets by taking parallel streets whenever possible. You can get free city and transportation-route maps at municipal information booths.
Rome's integrated transportation system includes buses and trams (ATAC), Metropolitana (subway, often nicknamed the Metro), suburban trains and buses (COTRAL), and some other suburban trains (Trenitalia) run by the state railways. A ticket (BIT) valid for 100 minutes on any combination of buses and trams and one entrance to the Metro costs €1.50.
Tickets are sold at tobacco shops, newsstands, some coffee bars, automatic ticket machines in Metro stations, some bus stops, in machines on some buses, and at ATAC ticket booths. You can purchase individual tickets or buy in quantity. It's always a good idea to have a few tickets handy so you don't have to hunt for a vendor when you need one. All tickets must be validated by time-stamping in the yellow meter boxes aboard buses and in underground stations, and immediately prior to boarding. Failure to validate your ticket will result in an on-the-spot fine of €50. Pay the ticket controllers on the spot; otherwise, it'll cost you €100 or more to pay it later.
A BIG ticket—or Biglietto integrato giornaliero (integrated daily ticket)—is valid for one day (the date it is stamped, not 24 hours) on all public transport and costs €6. A three-day pass (BTI)—or Biglietto turistico integrato—costs €16.50. A weekly ticket (settimanale, also known as CIS) costs €24 and gives unlimited travel on ATAC buses, COTRAL urban bus services, trains for the Lido and Viterbo, and subway (Metro). There's an ATAC kiosk at the bus terminal in front of Termini station.
If you're going farther afield, or planning to spend more than a week in Rome, think about getting a BIRG regional ticket or a CIRS (regional weekly ticket) from the railway station. These give you unlimited travel on all state transport throughout the region of Lazio. This can take you as far as the Etruscan city of Tarquinia or medieval Viterbo.
The Metropolitana (or Metro) is the easiest and fastest way to get around Rome. There are stops near most of the main tourist attractions (street entrances are marked with red "M" signs). The Metro has two lines—A and B—which intersect at Termini station. Line A runs from the eastern part of the city, with stops, among others, at San Giovanni in Laterano, Piazza Barberini, Piazza di Spagna, Piazzale Flaminio (Piazza del Popolo), and Ottaviano/San Pietro, near the Basilica di San Pietro and the Musei Vaticani. Line B has stops near the Colosseum, the Circus Maximus, the Pyramid (Ostiense station and trains for Ostia Antica), and the Basilica di San Paolo Fuori le Mura. The Metro opens at 5:30 am, and the last trains leave the last station at either end at 11:30 pm (on Friday and Saturday nights the last train leaves at 1:30 am).
Although not as fast as the Metropolitana, bus travel is more scenic. With reserved bus lanes and numerous tramlines, surface transportation is surprisingly efficient, given the volume of Roman traffic. At peak times, however, buses can be very crowded. If the distance you have to travel is not too great, walking can be a more comfortable alternative. ATAC city buses are orange, gray-and-red, or blue-and-orange; trams are orange or green. Remember to board at the rear and to exit at the middle: some bus drivers may refuse to let you out the front door, leaving you to scramble through the crowd to exit the middle or rear doors. Don’t forget you must buy your ticket before boarding, and stamp it in a machine as soon as you enter. If you find the bus too crowded to get to the ticket machine, write the date and time you boarded on the ticket where you would normally validate it. The ticket is good for a transfer and one Metro trip within the next 75 minutes. Buses and trams run from 5:30 am to midnight, plus there's an extensive network of night buses throughout the city.
The bus system is a bit complicated to navigate due to the number of lines, but ATAC has a website (www.atac.roma.it) that will help you calculate the number of stops and bus route needed, and even give you a map directing you to the appropriate stops. To navigate the site, look for the British flag in the upper right-hand corner to change the website into English.
ATAC urban buses (06/57003. www.atac.roma.it.)
COTRAL (800/174471 or 06/72057205. www.cotralspa.it.)
Trenitalia suburban trains (892021; 06/68475475 from abroad. www.trenitalia.it.)