Along Chicago's Kennedy Expressway, still miles from O'Hare Airport, signs that usually warn of traffic accidents and weather delays are now flashing unlikely advisories about hair gel and lotion. And it's impossible to miss the "Orange Alert" sign in red letters at the airport's entrance.

O'Hare is always busy, but the fog blanketing the city was, or course, just part of the reason for the delays. Two hours was not uncommon. By mid-afternoon, the large bins set out near security checkpoints for as-of-today not allowed water bottles and lip gloss were no longer overflowing, as they had been earlier. Alert travelers packed those in their checked luggage. Bags awaiting screening by the TSA often outnumbered passengers.

O'Hare has 11 flights into London today. The morning trip was canceled. Passengers arriving for evening and night flights were hopeful their vacations would be spared.

The TSA screening manager at the American Airlines terminal credited travelers for adapting quickly to the new rules. There was little anger and an abundance of understanding, he told me, something he says he doesn't see very often.