In a development that should shock no one, when facing drastic fines for leaving passengers stranded on the runway, airlines are largely abandoning the practice. May was the first full month when airlines faced the Department of Transportation's new fees, which could be as high as $27,500 per traveler. How did they change air travel?

Bloomberg reports on the stats:

Five flights were delayed in May, down from 34 in the same month a year earlier, the second-lowest total since the Transportation Department began collecting data on the delays in October 2008, according to a report on the agency's website.

That's a decline of 85%! Fantastic! Not so fast. When this new rule was created, more delays were anticipated. The Transportation Department confirms this fear. May 2010 had a 79.9% on-time record, while the prior year had an 80.5% rate. Of course, that's not a huge difference, but 34 flights aren't that many left on the tarmac to begin with.

And if you drill down into the causes for delay, then the evidence becomes even clearer. The logic behind additional delays is easy. If you have the passengers boarded waiting for takeoff, but then discover you can't depart for a few hours, you have to unload them. That creates a longer delay than if they just sat on the runway and took off as soon as possible, since re-boarding is necessary.

Unfortunately, the DOT doesn't appear to provide data on duration of delay, but it does tell you what portion of delays are caused by aircraft arriving late, which would be more prevalent if delays are longer, due to a domino effect it would cause. That was up in May 2010, accounting for 6.5% of the delays, compared to 5.8% in May 2009.

Are additional delays worth not having to sit on the tarmac? That depends on your opinion. But it's useful to note that such changes don't occur in a vacuum.

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