I came home from my trip shaken by what I had seen.

Almost everywhere I stopped — gas stations, rest stops and hotels, across Maryland, West Virginia, Pennsylvania, Ohio, Indiana and Illinois — there was a sign on the door saying that people had to wear masks to enter. And almost everywhere, most people ignored the sign.

At a Fairfield Inn in Ohio, a middle-aged couple sat unmasked on a lobby sofa for hours, drinking beers and scrolling through their phones. The hotel staff evidently did nothing about it. At a convenience store in Indiana, a hand-drawn sign on the door read: “Face masks are required. Please do not enter without one!!” Customers did anyway.

Nationwide, about half of Americans are not wearing masks when in close contact with people outside their households, according to a survey released yesterday by the University of Southern California.