Many air travelers in the United States gladly pay extra -- a LOT extra -- to ride in first class rather than coach. There, they enjoy roomier seats, faster boarding, and free drinks. Now the pay-to-be-pampered idea has come to America's interstate highways as well.

Many of these high-speed roads already have special, uncrowded "HOV" or "high-occupancy-vehicle" lanes. They're open only to drivers of vehicles carrying two or more, or sometimes three or more, people. The idea is that many lone drivers in the congested lanes will join a car pool so that they, too, can enjoy life in the fast lane.

Problem is, most lone drivers just won't give up their cars. And they're getting angrier and angrier at the lucky drivers zipping along in the HOV lanes. So to appease them -- and to ease traffic congestion -- a concept called "HOT lanes" is being tested in several cities.

"HOT" stands for "high-occupancy toll," and here's how it works: As usual, drivers of cars with multiple occupants pay little or nothing in the HOT lanes. But for a steep additional toll, single drivers can use them, too. Like first-class airplane passengers, many people say it's a charge they'll happily pay to whiz to and fro with less hassle.

Officials argue that the extra money lone drivers kick in for access to the HOT lanes helps pay for other transportation improvements, like light-rail lines.

But what if so many lone drivers jump at this chance that HOT lanes become just as jammed and slow-moving as regular lanes? Won't that defeat the whole idea of rewarding car-pooling drivers?

American capitalism has the answer. If single drivers start plugging up the HOT lanes, just keep on raising their tolls until enough of them slink back to the highway equivalent of the coach section.