The Roadfood.com screen name of Steve Koenigsberg, travelin’ man, has become a commonly used verb among seekers of regional American food. It dates back to 2008, when Mr. Koenigsberg took a road trip between Christmas and New Year’s with an itinerary of good restaurants at which he wanted to eat. But because of the holidays, an inordinate number of them were closed. To be travelin’ manned is to arrive at a much-anticipated roadfood destination only to find the door locked.