The USA can be crossed within five hours from east to west and within two to three hours from north to south. Strong competition between airlines has resulted in a wide variance in airfares. Categories of fares include first-class, economy, excursion and discount. Night flights are generally cheaper.

Budget airlines offering domestic flights have expanded service as larger national airlines have struggled financially in recent years. If travelling domestically, check fares for Frontier (www.flyfrontier.com), JetBlue (www.jetblue.com), Southwest (www.southwest.com), Spirit (www.spirit.com) and Virgin America (www.virginamerica.com).

There are extensive water communications along the coastline and along the grand rivers and lakes. The Ohio River is said to carry more water traffic than any other inland waterway in the world. Tour ships and passenger and freight lines crisscross all the Great Lakes from ports in Duluth, Sault Sainte Marie, Milwaukee, Chicago, Detroit, Buffalo, Rochester, Cleveland and Toronto.

The USA Rail Pass (tel: +1 800 872 7245; www.amtrak.com/rail-passes) is specifically designed for international travellers from outside the USA or Canada. It offers 15, 30, or 45 days of unlimited national travel.

The California Rail Pass allows seven days of travel in a 21-day period within California.

Driving is a marvellous way to see the USA but distances can be huge, eg 4,716km (2,930 miles) between San Francisco and New York City. Nevertheless, for those visitors with ample time, travelling by road is an ideal way to get a sense of both the vastness and the diversity of the country. Besides, road tripping is a favourite method of travel for Americans, and some of its great roads are iconic, such as the famous Route 66.

Hiring self-drive campers or motorhomes, called 'recreational vehicles' or RVs in the USA, is easy, and there are at least four different sizes of RV, from compact to large. Prices for RV rentals vary considerably, much according to the same kinds of factors that affect flight pricing: seasonality, location of rental and destination, and current availability. Booking early is recommended. Cruise America (www.cruiseamerica.com) has more than 100 rental sites across the USA where you can pick up or drop off vehicles.

Streets and roads in towns and cities are typically maintained by local authorities. Interstates are managed and maintained by state and federal authorities.

As with trains, coach is not a particularly fast method of travel in the USA, but there are many service options, especially in the northeastern United States.

Greyhound (tel: +1 214 849 8100; www.greyhound.com) and Trailways (tel: +1 877 908 9330; trailways.com) provide national service. 'Budget buses' such as BoltBus (tel: +1 877 265 8287; www.boltbus.com) and Megabus (tel: +1 877 462 6342; us.megabus.com) provide regular service between major cities.

Taxi service varies considerably from one city to another, and is often not available in rural areas at all. In big cities, taxis are readily identifiable and easily found. In smaller cities and towns with taxi service, you may need to call a company to request a taxi. If staying in a hotel, your concierge should be able to assist you with such a request.

An International Driving Permit is recommended, though not legally required. A full national driving licence is accepted for up to one year. All travellers intending to hire or drive vehicles in the USA are advised to ensure that the insurance policy covers all drivers and passengers

A yellow 'non-resident, interstate liability insurance card', which acts as evidence of financial responsibility, is available through motor insurance agents. Additional Collision Damage Waiver covering the car itself is also strongly recommended; in some states this extra insurance is included in hire rates by law.

The speed limit is usually 105-112kph (65-70mph) on interstate highways (motorways), but varies from state to state. Speed limits are clearly indicated and strictly enforced, with heavy fines imposed. It is illegal for drivers not to have their licences immediately to hand. Vehicle registration (usually found in the glove box of rental cars) is also typically requested by police officers during traffic stops.

If stopped, do not attempt to pay a driving fine on the spot (unless it is demanded), as it may be interpreted as an attempt to bribe. There are extremely tough laws against drinking and driving throughout the USA. Seatbelts must legally be worn in most states.

AAA (American Automobile Association) (tel: +1 800 222 4357; www.aaa.com). Service charges apply. Major national rental car agencies generally provide roadside assistance in the event of a problem with your rental.

Major international companies have offices at all gateway airports and in most cities. A drop-off charge is likely to be added if the car is deposited in a different city from the one in which it was hired. The minimum age for hirers is 25, but some companies allow younger drivers for an additional fee. Be sure to ask in advance about insurance policies; coverage requirements vary by state.

Travelling by bike is not the easiest way to see the USA, as interstates and many major roadways prohibit cyclists from riding alongside vehicles. Within cities and towns however, there is a growing bike culture, with the addition or expansion of bike lanes. Should you choose to travel by two wheels, be sure to wear a helmet and have appropriate safety equipment, such as lights, on your bike.

The speed limit is usually 105-112kph (65-70mph) on interstate highways (motorways), but varies from state to state. Speed limits are clearly indicated and strictly enforced, with heavy fines imposed. It is illegal for drivers not to have their licences immediately to hand. Vehicle registration (usually found in the glove box of rental cars) is also typically requested by police officers during traffic stops.

If stopped, do not attempt to pay a driving fine on the spot (unless it is demanded), as it may be interpreted as an attempt to bribe. There are extremely tough laws against drinking and driving throughout the USA. Seatbelts must legally be worn in most states.

There are numerous underground train systems in operation in major cities including New York (subway), Washington, DC (metro), Boston ('T'), Chicago (train) and San Francisco (BART - Bay Area Rapid Transit); others are being planned or built. There are also several tramway and trolleybus systems, including the much-loved antique trams found in San Francisco, although in many cities a car is needed to get around, due to lack of public transport.