By Plane

For long-distance trips, the most efficient way to get around the United States is by plane, even in these days of increased security and poor airline service.

By Car

Unless you plan to spend the bulk of your vacation in a city where walking is the best way to get around (read: New York City or New Orleans), the most cost-effective way to travel is by car. Even with skyrocketing gas prices in 2008, U.S. residents still pay less per gallon of gas than most of the rest of the world.

The interstate highway system connects cities and towns all over the country; in addition to these high-speed, limited-access roadways, there's an extensive network of federal, state, and local highways and roads.

If you plan on driving your own car over a long distance, then automobile-association membership is recommended. AAA, the American Automobile Association (tel. 800/222-4357; www.aaa.com), is the country's largest auto club and supplies its members with maps, insurance, and, most important, emergency road service. The cost of joining is $58 for a single member ($48, plus a $10 enrollment fee).

If you're visiting from abroad and plan to rent a car in the United States, keep in mind that foreign driver's licenses are usually recognized in the U.S., but you should get an international one if your home license is not in English.

Check out Breezenet.com, which offers domestic car-rental discounts with some of the most competitive rates around. Also worth visiting are Orbitz, Hotwire.com, Travelocity.com, and Priceline, all of which offer competitive online car-rental rates.

These national companies have offices at most airports and in many cities. You must have a valid credit card to rent a vehicle. Most also require a minimum age, ranging from 19 to 25 (some companies that will rent to the under-25 crowd will nevertheless assess underage driving fees of up to $25 per day extra), and some also set maximum ages. Others deny cars to anyone with a bad driving record. Ask about rental requirements and restrictions when you book, to avoid problems later.

Car-rental rates vary even more than airfares. The price you pay depends on the size of the car, where and when you pick it up and drop it off, the length of the rental period, where and how far you drive it, whether you purchase insurance, and a host of other factors. A few key questions could save you hundreds of dollars; you should comparison-shop and be persistent because reservations agents don't often volunteer money-saving strategies.

  • Is a weekly rate cheaper than the daily rate? If you need to keep the car for 4 days, it may be cheaper to keep it for 5, even if you don't need it that long.
  • Does the agency assess a drop-off charge if you do not return the car to the same location where you picked it up? Is it cheaper to pick up the car at the airport instead of a downtown location?
  • How much tax will be added to the rental bill? Local tax? State use tax? Some states' rental-car taxes can top 25% of the base rate, so be sure you know exactly how much you'll be paying in total before making a decision. Recently, many online booking sites have begun posting the total rental price of a car instead of just the base rates.
  • What is the cost of adding an additional driver's name to the contract?

Before you drive off in a rental car, be sure you're insured. Hasty assumptions about your personal auto insurance or a rental agency's additional coverage could end up costing you tens of thousands of dollars -- even if you're involved in an accident that was clearly the fault of another driver.

If you already hold a private auto insurance policy, you are most likely covered for loss of or damage to a rental car, and liability in case of injury to any other party involved in an accident. Be sure to ask whether your policy extends to all persons who will be driving the rental car, how much liability is covered in case an outside party is injured in an accident, and whether the type of vehicle you are renting is included under your contract.

The basic insurance coverage offered by most car-rental companies, known as the Loss/Damage Waiver (LDW) or Collision Damage Waiver (CDW), can cost as much as $20 per day. It usually covers the full value of the vehicle with no deductible if an outside party causes an accident or other damage to the rental car. In many states, you will probably be covered in case of theft as well (ask before making any assumptions). Liability coverage varies according to the company policy and state law, but the minimum is usually at least $15,000. If you are at fault in an accident, however, you will be covered for the full replacement value of the car but not for liability. Some states allow you to buy additional liability coverage for such cases. Most rental companies require a police report to process any claims you file, but your private insurer is not notified of the accident.

Most major credit cards offer some degree of coverage as well -- if they were used to pay for the rental. Terms vary widely, so be sure to call your credit card company directly before you rent.

If you're uninsured, your credit card provides primary coverage as long as you decline the rental agency's insurance. That means the credit card will cover damage or theft of a rental car for the full cost of the vehicle. (In a few states, however, theft is not covered; ask specifically about state law where you will be renting and driving.) If you already have insurance, your credit card will provide secondary coverage -- which basically covers your deductible.

Credit cards will not cover liability, the cost of injury to an outside party, and/or damage to an outside party's vehicle. If you do not hold an insurance policy, you may seriously want to consider purchasing additional liability insurance from your rental company, even if you decline collision coverage. Be sure to check the terms, however: Some rental agencies cover liability only if the renter is not at fault; even then, the rental company's obligation varies from state to state.

Other Transportation Options -- Traveling the U.S. in a recreational vehicle (RV) is an increasingly popular way of seeing the country. One good RV-rental agency with locations all over the country is Cruise America (www.cruiseamerica.com). It would take dozens of pages to thoroughly discuss the ins and outs of RV travel, so if you're thinking of hitting the road this way, check out Frommer's Exploring America by RV and RV Vacations For Dummies.

If you're more of the Easy Rider sort and have dreams of cruising the country on a motorcycle, know that you'll need a special motorcycle license and that almost every state also requires that riders wear a helmet. The best outfit for renting a bike nationwide is EagleRider (tel. 888/900-9901; www.eaglerider.com).

By Train

Long-distance trains in the United States are operated by Amtrak (tel. 800/USA-RAIL [872-7245]; www.amtrak.com), the national rail passenger corporation. Be aware, however, that with a few notable exceptions (for instance, the Northeast Corridor line btw. Boston and Washington, D.C.), intercity service is not particularly fabulous. An (expensive) exception is the high-speed Acela Express train that runs from Boston to Washington. Delays are common; routes are limited and often infrequently served. That said, if time isn't an issue, train travel can be a relaxing and scenic method of traveling. If you choose to travel by train, do it for the experience, not for the convenience.

Amtrak offers a USA Rail Pass, available for travel within three different regions, or the entire United States. Depending on the region, they offer 15-day and 30-day passes for unlimited travel. Travel must begin within 180 days of the date the pass is issued. They also offer a California and a Florida Rail Pass, and various regional tour packages.

You can also ride the "Auto Train," which is just what it sounds like: You drive your own car onboard a train in Sanford, Virginia, spend the trip in a standard train car, then drive off in Central Florida.

Amtrak also offers rail/fly packages that allow travelers to fly to their destination in one direction and to take the train in another.

By Bus

Bus travel is often the most economical form of public transit for short hops between U.S. cities, but it can also be slow and uncomfortable -- certainly not an option for everyone (particularly when Amtrak, which is far more luxurious, offers similar rates). Greyhound/Trailways (tel. 800/231-2222; www.greyhound.com), the sole nationwide bus line, offers several pass and discount options geared to domestic travelers. Their Discovery Pass (www.discoverypass.com) covers travel on all Greyhound routes in the U.S. and some in Canada.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.