A rule meant to lower the number of flight delays has actually backfired according to researchers. In 2010, the federal government set in place a rule to protect airline passengers from being stuck inside a plane on the ground without being able to leave for hours on end. Several horror stories of people being trapped on a plane for several hours with the airport in sight drew the attention of federal regulators to force airlines to have plans in place to avoid the situation. The tarmac delay rule says that airlines can face fines of up to $27,500 per customer if a plane is stranded out on a tarmac for more than three hours. But researchers at MIT and Dartmouth found that the rule may have inadvertently created more headaches.

Earlier this year, the Department of Transportation slammed Southwest Airlines with a $1.6 million fine for violating the tarmac delay rule. In order to avoid these hefty fines, airlines are canceling flights altogether instead of risking violating the rule. Incidents of planes being stuck outside the gate have gone down dramatically, the researchers found; from 1,654 cases in 2007, to just 17 between 2011 and 2013. At the same time, however, flight cancellations and delays are up.

The researchers suggested some ways to fix the issue, like extending the tarmac delay limit to three and a half hours and only applying the rule to flights before 5 p.m.