By BRENDA D. FARRELL
The Associated Press

Ladies and gentlemen, start your engines. If you're one of the 70 percent of Americans surveyed by the National Travel Monitor who say they want to add some adventure to their travel plans, then an auto or RV trip through Europe could put you on the road to the perfect vacation.

Dr. Eldad Boker, a professor of travel-tourism management at Johnson & Wales University, says driving through many European countries has never been easier.

''Much of Western Europe has very good signage and well-developed highway systems,'' Dr. Boker says. ''If you have an independent, adventuresome spirit, there are plenty of good reasons to see Europe the way most Americans tour the United States -- behind the wheel, on the open road.''

Making reservations

Before renting a vehicle, however, Dr. Boker says you should keep a few things in mind.

''Tell your travel agent which countries you plan to visit, and ask whether you need to obtain an international driver's license.

And when visiting major cities, it's best to drive to the outskirts of the city, leave your car in a parking garage, and take public transportation while visiting the metropolitan area.''

Auto Europe, a company that American travel agents use to reserve autos and RVs for their clients, offers these additional tips:

Save money, book ahead. You can save as much as 50 percent when you book your car rental before you leave for your vacation. And, Dr. Boker says, you'll have a guaranteed price.

Beware of the ''bait and switch.' Some rental companies do not quote all the mandatory surcharges, taxes and fees in their prices. The ''bargain'' rates you find on the Internet could end up costing a lot more. Dr. Boker says you should always obtain written confirmation of the final price before you leave home.

Compare Audis to Audis. When comparing rental rates, make sure the cars are of comparable size and quality, and that the same taxes and surcharges are included in the rates.

Sizes may vary. A car that is considered of intermediate size in one country could be classified as a compact in another. As a general rule, small cars are even smaller in countries outside of North America. When making a reservation, concentrate on the number of passengers and the amount of luggage a car can carry.

No guarantees

''I reserved a Porsche. This is a Ferrari.'' Although Dr. Boker says he has never had a problem, European companies confirm rental cars by category only. None guarantee that you will receive a particular make or model.

Don't get stuck with a stick. Rental cars in other countries always have manual transmissions, unless the voucher specifically states that an automatic has been reserved.

You can't get there from here. When making a reservation, be sure to disclose every country you will visit by car. Italy has restrictions on luxury cars crossing its borders, and most car rental companies prohibit travel into Eastern Europe.

Round trips are cheaper. Drop charges (one-way fees) can be substantial in Europe.

Double-check your insurance policy. Credit card insurance programs are full of exceptions, and they change. If you want to take advantage of yours, call the card issuer and request written details of your coverage. Mr. Boker adds that not all countries will honor credit card insurance programs, and you should double-check with your travel agent before you embark on your vacation.