Airports may be jammed with airplane gridlock, but that hasn’t stopped some airlines from actually increasing flights.

United has announced it’s adding 35 flights a day and six new routes from Denver, including Dayton, Ohio, Greensboro, North Carolina, Lexington, Kentucky, San Juan, Puerto Rico and Montego Bay, Jamaica.

And Delta announced its largest transatlantic expansion in history. The airline now has 650 weekly flights across the Atlantic to Europe. That’s a 30% increase from last year with 77 routes and 32 destinations in Europe.

This includes Geneva, Venice, Prague, and non-stop flights from Los Angeles to Paris.

Now the challenges are airfare prices and on-time reliability.