It’s funny how we fall into bad patterns. Consider this scenario. You’re going on a weeklong business trip, so you drive to the airport, leave your car in long-term parking, and come back to find it waiting patiently but with $100 due to the cashier. It seems normal, but in actual fact you’ve paid a lot of money for an expensive asset to do nothing at all.

Alternatively, you get a ride in a cramped van, and pay a premium both ways. Not fun, is it?

FlightCar, inspired by AirBNB, is trying to change the equation with a peer-to-peer solution from the sharing economy. In this case, you drive to the airport as normal, but instead of heading for the parking lot you go to an off-site lot operated by FlightCar (now at 17 airports in the U.S., and probably 25 by the end of the year).

the airport busThe bus to the Cardiff, Wales airport lot — and a big bill. (Photo: Holidayextras/flickr)

You leave your keys, hop into an on-demand FlightCar van or SUV shuttle and get delivered to your flight. Meanwhile, your car is back there earning its keep. According to Ryan Adlesh, head of expansion at FlightCar, the company treats your car as a temporary rental unit. Arriving passengers can rent it (at a claimed 30 to 40 percent discount over legacy car rental) while you’re away.

Think about it: Cars stay in long-term parking an average of four or five days, and the big picture is that they're idle more than 90 percent of the time. In the FlightCar alternative the owner is paid five to 20 cents per mile, with an average payment of $20 to $30. And when they get back there’s no parking fees, but a washed and vacuumed car sitting there waiting.

Here's how it works on video. The acting is a bit cheesy, but the point comes across:

FlightCar, launched in 2013, is already operating at international airports in Newark, San Francisco, San Diego, Portland, Seattle, Philadelphia, Dallas/Fort Worth, Boston and Baltimore, among others. At Newark, for instance, there’s currently a fleet of 18 cars, so you should be able to find one that suits. Next up is Canada and Europe.

There’s a flat-rate monthly program, too, which can net the driver $250 or more. Of course, there’s an app, which lets you share your car or rent on via your phone, or pinpoint the shuttle’s arrival time. “The whole model is not to have cars sitting in parking lots,” Adlesh said. He added that the company is so far attracting mostly leisure travelers, flight crews and seniors — business people can expense parking, so the advantage is not as obvious.

Tesla, BMWs and Mercedes are among the cars shared, but as in a traditional rental you’ll pay more for those rides. The only thing you’ll need to keep in mind is that the car needs to be back in the lot when the owner returns. Obviously, the system won’t work unless FlightCar keeps close track of all those flights inside and out.

Jim Motavalli ( @jmotavalli ) writes about cars, technology and the environmental world to anyone curious enough to ask.