Termini station is the main hub of Rome's transport system. The city transport authority, ATAC (tel: 06 57003 or 06 4695 2087; www.atac.roma.it), operates the city's large fleet of buses and trams. The network consists of over 300 bus lines and six tram lines, which cover the entire city and run daily 0530-2400. After 2400, there are plentiful night bus routes.

The regional transport authority Cotral (tel: 800 174 471; www.cotralspa.it) runs buses throughout the Lazio region. Another company, Met.Ro (tel: 800 431 784; www.metroroma.it) is responsible for three suburban railway lines departing from Termini, Ostiense and Flaminio stations (and going to Pantano, Lido di Ostia and Viterbo respectively), and Rome's two metro lines (A and B), which cross at Termini station. The easily mastered metro service operates daily 0530-2330 (until 2430 Saturday). Line A has closed at 2100 for engineering works for the last three years, but these should be completed in 2009. After 2100 there are two replacement bus services in place, MA1 from Battastini to Arco di Travertino and MA2 from Viale G Washington to Anagnina. Plans to build a third line have been in the works for years; don't expect it to open until at least 2011. Just extending the two existing metro lines proved to be trouble enough, with the uncovering of archaeological vestiges either postponing or preventing any advances.

Night buses run daily 0000-0530, along 22 routes, and are marked on bus stops (fermata) and buses with the letter ‘N', as in 40N or 60N.

All tickets must be pre-purchased and are available for sale at ATAC counters, tabacchi (newsagents, which can be recognised by their large white and black T sign) and at automatic ticket dispensers at metros. Tickets should be validated at the beginning of the journey (to avoid a hefty on-the-spot fine should a controller check your ticket). The cheapest ticket, the Biglietto Integrato a Tempo (BIT) is valid for up to 75 minutes of travel on ATAC buses and trams, or for one trip on the metro or suburban train lines.

Day (BIG) and week (CIS) passes are valid on all transport in the municipality. Monthly passes are also available. The Biglietto Turistico (BTI) is ideal for those staying only for two or three days, or a long weekend. It's valid on buses, trams, the metro and local trains within Rome. The BIRG pass covers a day's worth of transport within the whole Lazio region, and cost varies depending on the number of zones covered. Alternatively, see Roma Pass under Sightseeing for a ticket that covers transport and museums.

Taxi ranks are located at various points around the city centre, though there are notoriously never any when you most need them. Visitors are advised to use only the yellow and white official taxis. Surcharges are applied for each item of luggage, night service (2200-0700), on Sundays, public holidays, and for out-of-town journeys, except for airport transfers, which now have fixed rates whatever the time of day. While taxis may be called by telephone, the meter is turned on immediately after the call and not on pick-up. Tipping of 5-10% is gratefully received, although Italians often do not bother.

Companies include Radio Taxi 3570 (tel: 06 3570; www.3570.it), Radio Taxi Samarcanda (tel: 06 5551; www.samarcanda.it), and Pronto Taxi (tel: 06 6645).

The interweaving paths of mopeds, pedestrians and trams, the erratic driving, the one-way systems and the frequent traffic jams make driving in Rome an experience that is best avoided. The authorities have reacted to traffic congestion (and the ensuing pollution) by cutting off large areas of the city centre to non-resident traffic during business hours, and (to a lesser extent) in the evening. Exceptions are usually made for visitors driving to their hotel.

Parking is as problematic as driving, as it's very tricky to find spaces. Pay-and-display meters charge about €1 per hour (although the fee may be waived in the evenings and at weekends). There are various underground car parks in the city - the one at Villa Borghese is open 24 hours. If you're tenacious and lucky, you may snap up a free parking space but anything marked Sosta Vietata (no parking) is to be avoided - the municipal police have a nasty habit of towing away or, even worse, clamping illegally parked cars and then charging a huge sum for their return. Unlucky owners should contact the municipal police (tel: 06 67691).

Most car hire companies require drivers to be over 25, though some accept drivers aged 21 and up (with a per day surcharge for drivers aged under 25). A valid EU licence or an International Driving Permit, and credit card number or cash deposit are requested. Full insurance is advised. Providers include Avis (tel: 06 452 108 391; www.avisautonoleggio.it), Europcar (tel: 199 307 030; www.europcar.it), Hertz (tel: 02 6943 0006; www.hertz.it), Sixt (tel: 06 659 651 or 199 100 666 ; www.e-sixt.it), and the locally based Maggiore (tel: 199 151 120 or 06 2245 6060; www.maggiore.it), which also rents environmentally friendly electricity-operated cars. All have various locations throughout the city.

Bicycles, scooters and motorbikes are available for hire at Bici & Baci, Via del Viminale 5 (tel: 06 482 8443; www.bicibaci.com). Scooters are also available at Scooter Hire, Via Cavour 80 (tel: 06 481 5669), and Treno & Scooter, Termini Train Station, next to platform 1 (tel: 06 4890 5823; www.trenoescooter.com). RomaRent, Vicolo   de' Bovari 7A, near Campo de' Fiori (tel: 06 689 6555), has scooters, bicycles and cars for hire.