In the rush to solve mainstream media stories about airline passengers sitting on the place on the tarmac for hours and hours, the U.S. Department of Transportation's 2010 Tarmac Delay Rule glossed over concerns that it would lead to more delays and cancellations - exactly what has happened.

As a result, it takes most air passengers far more time to reach their destination for all pasangers than ever occurred for a few during lengthy tarmac delays, according to a study in Transportation Research Part A: Policy and Practice.

Amid pressure from consumer advocacy groups, the DOT enacted the rule in 2010 in an effort to improve passenger welfare, but faced with potentially large fines, airlines were widely expected to cancel many flights when delays become too long. The rule stipulates that commercial aircraft lift off or allow passengers to deplane no later than three hours after the cabin door closes at the departure airport, and that passengers be allowed to deplane no later than three hours after touchdown at the arrival airport. The rule aims to protect passengers from excessively long delays on the tarmac upon taxi-out or taxi-in, and monetarily penalizes airlines that violate the three-hour tarmac time limit.

The scholars of the new paper used actual flight schedule and delay data from 2007 before the rule was enacted, and compared these delays to those estimated for hypothetical scenarios with the rule in effect for that same year. The results show that the rule has been highly effective in decreasing tarmac delays, especially long delays, but each passenger-minute of tarmac time saving is achieved at the cost of an increase of approximately three passenger-minutes in total passenger delays. This is due primarily to increases in flight cancellations, resulting in passengers requiring rebooking and often leading to extensive delays in reaching their final destinations.

Going forward, the researchers plan to examine the rule's impact on commercial airlines across different years, on commercial airline schedule decision-making and separately on international carriers, regional carriers, legacy carriers and low-cost carriers.