One way to avoid gouge rates is to book a hotel-plus-parking package near your departure airport the night before you leave. As an added benefit, a pre-departure night near your airport can help guarantee that you won't miss your flight because of weather or traffic. Hundreds of airport-area hotels offer packages that combine one night's accommodation with up to 30 days of "free" parking, although most stop at seven, 10, or 14 days — in the hotel's parking area, with shuttle service to/from the airport. Most hotels also let you take the overnight at the end of your trip if you plan to arrive on a very late flight. Most also provide for parking beyond the nominal limit for an extra daily charge.
— Park Sleep Fly (parksleepfly.com), the pioneer in the field, currently lists participating hotels near 109 large- and medium-size airports in the United States and six in Canada.
— Stay 123 (stay123.com) lists participating hotels near 115 U.S. airports and 17 in Canada.
— BuyReservations (buyreservations.com) posts accommodation/parking packages near 60 U.S. airports plus Montreal.
— Airport Hotels Free Parking (airporthotelsfreeparking.com) lists packages at 17 mostly-larger U.S. airports.
For the most part, Park Sleep Fly and Stay 123 list the same hotels, but not always. You might as well check all four agencies just in case any one agency doesn't cover all your options.
Also, many airport-area hotels and motels independently offer similar packages, but they're hard to find if they don't list on one of the nationwide sites. On my last trip, for example, I arranged a 14-day sleep-park package at Portland airport through my local AAA travel agency that isn't listed on any of the online sites. And you can Google "hotel parking packages at (wherever)" to find some independents.
Although the online blurbs often boast "free" parking, the one-night package room rate is almost always higher than the hotel's lowest available rate. But the difference in rates is much less than the cost of parking for a week in an airport-area parking lot: I've usually found the premium for a week or more of parking works out to only a few dollars a day, and much less than you'd pay at most big airports for just the parking.
At some airports, a parking package is a no-brainer. If you have to leave your car for a week at Seattle-Tacoma, for example, a $79.99 room at Econo Lodge, with seven days parking, is a better deal than the lowest weekly parking rate of $130 per week. On the other hand, long-term parking at Charlotte is just $5 a day, so the parking packages and independent lots can't provide much of an advantage. As in so many travel situations, you have to check all the options carefully before you buy.
The four online airport parking specialist agencies I list also say they offer similar deals at major cruise ports. But when you take a closer look, you find that most of the "cruise port" listings are actually for airport-area hotels with shuttles to/from the actual port area. And, in many cases, the "free" shuttle is one-way only: You pay for the return trip. Only a few hotels are actually near the port.
(Send e-mail to Ed Perkins at firstname.lastname@example.org. Perkins' new book for small business and independent professionals, "Business Travel When It's Your Money," is now available through http://www.mybusinesstravel.com or http://www.amazon.com)