With the government shutdown continuing, travel experts said it's possible that TSA wait times of more than three hours could persist.

Travelers missed their flights out of Houston Sunday as they stood, sat and waited in TSA lines wrapping around and out of airport terminals for as long as three hours.

A travel association has urged the U.S. Congress in a letter on Monday to reopen the federal government ahead of the Thanksgiving travel rush, as the shutdown stretches into its 34th day.