Sixty-five percent of Americans are more likely to take a road trip this summer than they were last summer, according to a recent survey by booking site Travelocity. But while a domestic road trip might appear like an affordable alternative to traveling abroad, costs can easily spiral out of control. A recent study by travel site Expedia found that Americans expect to pay an average of $898 per person for a weeklong trip within their own country, hardly chump change. To keep a lid on summer road-trip costs, we canvassed financial planners for their best tips, culled from personal experience. Here's what they had to say.

Use apps to your advantage
Not that long ago, travelers squinted at printed maps and missed exits. These days, there is no excuse for not using smartphone apps. Google Maps, for instance, will get you from Point A to Point B without getting lost and racking up unnecessary mileage. GasBuddy will locate the cheapest local stations where you can fill up the tank. Apps like RoadNinja and Roadtrippers can tell you about local amenities and help plan your route, and HotelTonight or Hotels.com can locate last-minute lodging discounts nearby.

Get campy
Ditch the hotels, and stay in campgrounds, says financial planner Therese Nicklas. By camping in state parks with her family of four for around $10 a night, and cooking their own food, Nicklas estimates they save about $150 every single day. Also consider an annual pass from the National Park Service, allowing you access to more than 2,000 sites nationwide for $80.

Hold money-saving competitions
Adviser Niv Persaud has an innovative idea for families: Make budgeting a game with your kids instead of a chore. "For each dollar they save, on coupons, special deals, or cheap gas, they earn a star," Persaud says. "The one with the most stars at the end of the trip gets to pick the location for the next family vacation."

Forget flights and car rentals
Whatever savings you realize by staying domestic could be wiped out by airline bookings and car- or RV-rental fees. So do what David MacLeod did, and schlep to your destination in your own car, even if it's a long distance away. The planner from Fullerton, California recently took his family all the way from southern California to Montana in their trusty Honda Odyssey, saving $1,000 in the process.

Bring your own food
The silent killer of many family travel budgets: Eating out. Nip that in the bud with a cooler or two stuffed to the brim with snacks and quick meals. "A simple gallon of milk, box of cereal, yogurts and fresh fruit can provide a great breakfast at 1/4 of the cost of eating out," says Janice Cackowski, a planner in Independence, Ohio. She also advises eating out only at lunch, when restaurant prices tend to be much lower.