Rome is quite a big city with a substantial metro area. Many Romans own scooters and mini cars (like the Smart car) that can drive down its ancient alleyways and park in tight spots. As a visitor or tourist in Rome, it is not recommended that you rent a vehicle, especially if it’s you’re first time there. Roma is a busy city and it will be difficult to find parking and avoid traffic in the areas surrounding Vatican City. Alternatives in Rome transportation system are abundant and cheap. Like most big cities in Europe, there are several modes of public transportation in Rome that will help you get around and visit the Vatican.The buses, light rail and metro all share the same ticket system. You can purchase a Roma Pass, a single ticket (includes transfers for over an hour) or a daily, weekly and even monthly pass.
Bus
The most common way to get around in Rome is buy bus. The buses go everywhere, are efficient and easy to use. Rome even has minibuses that get into the small alleys behind the famous Piazza Navona and right up to the Spanish Steps. Buy your bus and metro tickets in any tobacco store in Rome,in Termini station and some other locations around the city you can also use automatic machines to buy the tickets.
Tram/Light Rail
Rome also has two light rail lines. The tickets (and costs) are the same as the buses and these are a friendly means of transportation. If a line is under construction, Rome’s transportation authority (ATAC) will send buses to follow its exact route.
Metro
Currently there are two metro lines in Rome (a third line is being prepared) - Lines A and B.
Taxi
Note that there are fixed prices to and from the Airports. In the city make sure to ask the driver to put on the Meter and take a licensed taxi. You don't have to tip the taxi driver but it is customary to round up the bill tothe next Euro.
Rome Transport Apps
Smartphone and Tablet users can download free Android and iOS apps such as Roma Bus (in English) or Probus Rome that will not only tell you exactly when your next bus to the Vatican (or anywhere in Rome) is coming,but also help you plan your trip and tell you which bus to take and which transfers to make.
Getting to Rome from Rome’s Fiumicino International Airport (Leonardo da Vinci):
There are two train options, a bus and taxis. Your best bet is to take Leonardo Express train. It’s simpler and faster most other solutions and arrives at Rome Central Bus Station -Termini. The FM1 train and buses are a tad cheaper but slower, less frequent and don’t necessarily arrive at Termini. A taxi should cost 48 Eur (one way, current price)
Getting to Rome from Ciampino Airport
The easiest way to get to and from Ciampino is with a busrun by a company called Terravision. The bus connects Ciampino with Terministatio. A taxi to Ciampino should cost 30 Eur (one way)