If you're heading back to college—or sending a kid that way—you've got plenty of company.
And plenty of bills.
The U.S. Department of Education estimates that more than 21.5 million students will be enrolled in post-secondary schools this academic year.
According to the College Board's most recent survey, the price tag for tuition, fees, room and board was over $18,000 at a public four-year in-state college, $31,701 at a public four-year out-of- state college and close to $41,000 at a private nonprofit four-year college during 2013-14.
The price of getting a student to and from campus or visiting during parents' weekend isn't included in those tallies, but there are a few ways to keep a handle on those travel costs.
"The best tip for students and families who will fly to campus is to identify the airline with the best fares and availability and fly it exclusively in order to rack up frequent-flier miles," said Sarah Schupp of UniversityParent.com.
Plan as far ahead as possible, be flexible about the dates and times of travel "and find out if the college has free or low-cost shuttles to and from the airport," Schupp said.
It's been about two years since AirTran (now part of Southwest Airlines) and United Airlines ended programs offing discount fares or special bonus travel credits for students or young travelers. But Lufthansa continues to offer its Generation Fly program for students to travel to Europe and beyond.
The program promises special student fares and is open to college or university students in the United States and to people 12 to 25 years of age who have a valid college .edu or K12.[state].US email address.
Several student-oriented travel companies, such as Student Universe, STA Travel, operate much like other travel booking sites but also offer some negotiated airline discounts for college students and people under age 26.
"Even though most airlines provide discounted pricing for students, they only do so in limited quantities," said Paul Jacobs, a Student Universe spokesman. "The best prices can sell out, so don't wait if you find a price that is cheaper than you have seen elsewhere."
Students traveling to and from college via bus or train can get 10 percent discounts on Amtrak fares and 20 percent off Greyhound fares with the Student Advantage Card, which costs $22.50 per year (multiyear memberships are discounted) and offers savings at stores online and on campus. The International Student Identity Card offers a 10 percent discount on the lowest Amtrak fares as well.
Megabus and Bolt Bus offer discounted bus service (some tickets sell for as low as $1) for everyone to an increasing network of cities, and the route map includes many college towns. Shared-ride boards are also available at most colleges and universities.
When it comes to visiting a student at college,such as during parents' weekend or a major sporting event, check the college website for hotels or inns offering discounts. And always ask if there are any school-related discounts when making reservations on your own in a college town.
Less-traditional lodging options such as Airbnb and Vacation Rentals By Owner may also be an option. But Schupp advises parents not to buy any plane tickets or book hotel rooms until they've talked to their student about a visit because "they get busy with their new lives on campus and may have other plans."
—By Harriet Baskas, special to CNBC.com. Baskas is the author of seven books, including "Hidden Treasures: What Museums Can't or Won't Show You," and the Stuck at the Airport blog. Follow her on Twitter at @hbaskas. Follow Road Warrior at @CNBCtravel.