A city you cross on foot, and reach by car
Rome holds nearly three thousand years inside the Aurelian Walls, and almost everything a first visit wants to see sits within an area you can walk across in about an hour. That is the first thing worth knowing: the historic centre rewards walking and punishes driving. The second is that its two airports are not in the city at all, and the gap between them and your hotel is where most arrivals go wrong.
Fiumicino (Leonardo da Vinci, FCO) lies about 32 km southwest, on the coast. Ciampino (CIA) is closer, roughly 15 km southeast, and handles most low-cost flights. Civitavecchia, the cruise port, is around 80 km northwest, far enough that a ship calling for a day makes the journey the deciding factor of the whole visit.
How the centre is laid out
Think of the centre as three clusters that touch each other. Around the Colosseum and the Roman Forum lies the ancient city, open to the sky, best walked early before the sun and the queues arrive. Northwest of it, the historic centre proper: the Pantheon, Piazza Navona, the Trevi Fountain and Campo de' Fiori, a knot of narrow streets where no vehicle is much use. Across the Tiber stands the Vatican, with Saint Peter's and the Museums, and beside it Trastevere, which keeps the look of a village and fills up after dark.
Termini is the main railway station and the point where the two metro lines cross, which makes it the practical centre of gravity for arrivals even though it is not a place anyone visits for pleasure. Tiburtina, further out, handles many high-speed and coach services and is often cheaper to reach, but it sits outside the walls: worth checking before booking a train that leaves from there at dawn.
The ZTL, and why a car is a liability here
The historic centre is a limited traffic zone, monitored by cameras, active on weekdays and on weekend evenings. Entering without a permit means a fine that arrives months later, one for each gate crossed. Hotels inside the zone can register a plate for you, but only for the time it takes to drop luggage, and only if you give them the number in advance. Parking inside the walls is scarce and expensive, and the streets are cobbled, narrow and one-way in ways that no map reads well at speed.
The practical conclusion is simple: a car is useful for arriving, for leaving, and for the countryside around Rome. It is useless for the four or five days spent inside the city, and it costs money the whole time it sits still.
Getting in from the airports
From Fiumicino the Leonardo Express runs to Termini in 32 minutes, every 15 minutes, for 14 euros a head. It is fast and reliable, and it makes sense when you travel light and your hotel is near Termini. With luggage, small children, or an address in Trastevere or near the Vatican, the saving evaporates in the taxi you take at the far end.
Taxis charge a fixed fare to and from the airports when the journey starts or ends inside the Aurelian Walls: 55 euros from Fiumicino and 40 from Ciampino, for the car and not per person, luggage included, with no night or holiday supplement. It is worth knowing the number: it is the figure that tells you whether any other offer is reasonable. A private transfer books the same journey in advance at a known price, with a driver who waits inside arrivals and follows the flight if it lands late.
What is worth leaving the city for
Tivoli, about 30 km east, holds two UNESCO sites within a few kilometres of each other: Hadrian's Villa, the enormous country retreat of an emperor, and Villa d'Este, whose garden is built entirely around moving water. Ostia Antica, towards the sea, is the Roman port town, quieter and in places better preserved than Pompeii. The Castelli Romani, the hill towns south of the city, are where Romans themselves go to eat: Frascati for white wine, Castel Gandolfo above its volcanic lake, with the papal palace and gardens now open to visitors.
All three are awkward by public transport and straightforward by road. That is the honest division of labour in Rome: walk the centre, take the train when it goes where you are going, and keep the car for the day you leave the walls behind.