New Delhi, March 28 -- Maybe Dad was right about getting to the airport early. But it turns out there's still such a thing as TOO early.

Travelers panicked by scenes of never-ending lines at U.S. airport security checkpoints and frustrating tales of missed flights over the past few weeks are now showing up way before their departures. Some airports where the wait times have been manageable say those early birds are only adding to the misery - and in some cases causing other passengers to get to their gate too late.

In Ohio, John Glenn International Airport in Columbus is warning passengers against arriving hours in advance, even creating a chart showing when to show up: "90 minutes before departure is all you need."

The airport says th...