The prospects for a summer road trip are looking good. With the price of gas down 25 cents per gallon over the past month — and the price of airline tickets on the rise — hitting the road looks like a relatively economical vacation strategy. But before you pull out of the driveway, take these steps to ensure your long ride won't turn into a long list of expenses.

• Test Drive: It's easy to fall behind in your car maintenance, so vehicle preparation is essential. Check if you need the oil changed, tires inflated, or brakes adjusted. The cost of a visit to your local garage or oil-change chain now can save you a lot of money later, not to mention the hassle that comes with trying to mend something on the road. Also, make sure the spare tire is stocked and inflated.

• Get Backup:  Invest in an auto club membership such as AAA; the annual fee will be cheaper than the cost of getting a tow or (after you've locked your keys in the car) having a locksmith come by to get you back inside. Even cheaper: Certain auto insurers, including Geico and Progressive, provide the same emergency roadside service to customers at a fraction of an auto club's cost.

• Get directions: Not getting lost will save you gas money (not to mention time and your sanity). Purchase discounted maps at maps.com and navigate your route ahead of time on paper. If you have a GPS, be sure to store it in your glove compartment and lock it while you're away from the car (and don't tip off thieves with visible cables or tell-tale suction-cup marks on your dashboard or windshield) .

• Stay Fuel Friendly: Yes, the price of gas is cheaper than it was a month ago, but it's still a buck more than it was a year ago. So you'll need to know the best places to fill up. While you're on the road, use the GasBuddy app to find prices at nearby gas stations. To conserve fuel, pack the car lightly and use cruise control where possible. Gas mileage, according to fueleconomy.gov, also tends to decrease rapidly once you reach 60 mph. So each 5 mph you drive over 60 mph is like paying an additional $0.24 per gallon for gas.

• Go and Stop: If you insist on driving fast, you can at least try to save money on speeding tickets. The Trapster mobile app promises to tell you the location of speed traps and red-light cameras on your route (though some users complain that the app, um, crashes a lot). When it's time to break for lunch, use the SnapFinger app to locate cheap food and order takeout.

• Counter Irritability: Sure, you'll be cooped up in a car for long hours and will likely grow tired of gazing out the window, but finding fun, inexpensive ways to pass the time isn't hard. Stop by Toys "R" Us or a big-box department store to buy travel-sized board games for the kids in the back seat. Entertainment that's even more economical: Borrowing books on CD for free from the local library. Unabridged Harry Potter, anyone?

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