Dartmouth study: Tarmac-delay rule has disrupted airline operations

The rule implemented in 2010 that penalizes airlines for making passengers sit for more than three hours on the tarmac has resulted in longer travel delays, according to a Dartmouth University study.

The Department of Transportation rule requires airlines to pay fines each time a plane sits on the tarmac more than three hours after the door closes ahead of departure for domestic flights, and each time a plane sits on the tarmac for more than three hours after landing. Under pressure from consumer advocates, the DOT established the rule.

In “Tarmac Delay Policies: A Passenger-Centric Analysis,” the authors concluded that the rule has been highly effective in reducing long tarmac delays, but it has also caused an increase in flight cancellations, which lead to much longer overall delays due to the difficulties of rebooking.

All in all, Dartmouth said that each minute saved in tarmac delays has been countered by three minutes of delays related to additional cancellations.

In preparing the study, which appears in the January edition of the journal “Transportation Research Part A: Policy and Practice,” the authors compared actual flight schedule and delay data from before and after enactment of the rule to determine that long tarmac delays have been reduced.

To look at the impact on travel times that resulted from the three-hour rule, the authors developed a more complicated approach. Using an algorithm in combination with DOT data, they quantified passenger delays in 2007, before the rule went into effect. They then compared those delays to the delays that they estimate would have occurred had the rule already been enacted.

“Through our results and several sensitivity analyses, we show that the overall impact of the current tarmac-delay rule is a significant increase in passenger delays, especially for passengers scheduled to travel on the flights which are at risk of long tarmac delays,” the authors wrote in the study’s abstract.

The Dartmouth team also analyzed what the impacts would be of various changes to the tarmac-delay rule and suggest modifying it.

“This modified version involves increasing the tarmac time limit to 3.5 hours and only applying the rule to flights with planned departure times before 5 p.m.,” the Dartmouth team said. “Finally, in order to implement the rule more effectively, we suggest the tarmac time limit be defined in terms of when the aircraft begin returning to the gate instead of when passengers are allowed to deplane.”

When the tarmac-delay rule was implemented in 2010, airline executives warned that they would cancel more flights rather than face fines for rule violations.