Yesterday, the United States and U.S. Department of Transportation (DOT) disclosed a lawsuit against Southwest Airlines, accusing the airline of chronically delayed flights and interrupting passengers’ travels.

The Transportation Department is taking legal action against Southwest, alleging the airline illegally operated persistently delayed flights and disrupted passengers' travel plans.

The U.S. Transportation Department is suing Southwest Airlines and has fined Frontier Airlines over "chronically" delayed flights, disrupting passengers' travel and plans.

The calculation includes cancellations and diversions. "When an airline knows that a particular flight is consistently late, it is essential that the airline adjusts its schedule," the DOT said in its lawsuit,

The Transportation Department is stepping up enforcement of persistent flight delays with a lawsuit against Southwest Airlines and a fine against Frontier Airlines.