A rule intended to keep airline passengers from being stuck for long stretches on the tarmac has resulted in more delays, according to a study.

Dartmouth and the Massachusetts Institute of Technology found the tarmac delay rule increased flight cancellations and ultimately the time it takes for passengers to reach their destinations.

"We found that for every minute of tarmac time being saved there is, on average, a three-minute increase in the total passenger delay," said Vikrant Vaze, an assistant professor at Dartmouth's Thayer School of Engineering who co-authored the study.

Adopted in 2010, the Transportation Department rule requires that passengers be allowed to deplane within three hours of boarding or landing for domestic flights. Airlines are subject to fines of up to $27,500 per passenger for violations.

Hoping to avoid fines, airlines have been quicker to pull the plug on flights, Vaze said. That forces passengers to scramble to find another flight to reach their destination, something that has become increasingly difficult as industry consolidation reduces the number of available seats on planes. Flights that are not canceled have to start lining up anew after letting passengers deplane and then reboard, adding to the ultimate delay.

"Most of these extra delays are being felt by those exact same passengers," Vaze said. "It's just that they're not on the tarmac."

The study proposed lengthening the allowed delay window from 3 to 3 1/2 hours on domestic flights and excluding from the restrictions flights scheduled to depart after 5 p.m. to avoid cancellations and other delays.

Airlines for America, an industry trade organization, expressed support Monday for making tarmac delay rules less stringent.

"This study confirms what (Airlines for America) and our members have said all along — the tarmac delay rule has actually caused more harm than good for the traveling public," said Jean Medina, an Airlines for America spokeswoman. "The rigid structure of the rule in its current form has resulted in unnecessary delays in getting passengers to their intended destination, as carriers seek to avoid overly punitive fines from DOT."

The delay rule came in the wake of numerous passenger horror stories, including a February 2007 ice storm that left nine JetBlue planes stranded on the tarmac at John F. Kennedy International Airport in New York for more than six hours.

Since the rule took effect, the Transportation Department has issued $5.4 million in fines to airlines for violations, including failures to report a lengthy tarmac delay as required.

Southwest Airlines was hit with the largest of the fines last year — a record $1.6 million penalty — after passengers on 16 of its planes were stuck on the tarmac at Chicago's Midway Airport during severe weather in January 2014.

Henry Harteveldt, a travel industry analyst with Atmosphere Research Group, said that while the tarmac delay rule was "created with good intentions," it was time to take a fresh look at the restrictions.

"Certainly a passenger is ahead by not being stuck on an airplane going nowhere," Harteveldt said. "But that same passenger may be stuck in that city going nowhere and unable to get to their destination for hours, perhaps a day or two, based on where they're traveling and the time of year."

Harteveldt did not agree with one suggestion forwarded by the study — that restrictions be eased to allow planes to simply start back to the gate, as opposed to having passengers off the plane within the three-hour window. He said the trip back to the gate could be interminable in some cases.

"If you're sitting on a plane, you're sitting on a plane," Harteveldt said. "It doesn't matter if you're out on a runway or 20 feet from the terminal, you're still stuck."

The study was funded by a research arm of the Federal Aviation Administration.