Jane and Michael Stern, acclaimed authors of more than 20 books, contributing editors to Gourmet, foodie-foragers and road warriors par excellence, have hit the blacktop once more, this time cruising from sea to shining sea to sample and sort out the most stellar examples of sandwichery produced in our fair land. Roadfood Sandwiches is the result, a paean to culinary inventiveness as expressed by and eaten by ordinary people. Though the sandwich, two pieces of bread and a filling, was originated by the fourth Earl of Sandwich in the mid-18th century, it has become as American as apple pie (oops that has non-American origins, too), a casual, quick-to-fix meal or snack that can be consumed anytime, anywhere. Close to 100 humdingers are included, each with its provenance and perpetrators identified, each presented with the Sterns' signature enthusiasm and down-to-earth charm. They're arranged in alphabetical order from Amighetti Special, a St. Louis hero swathed in a super-special, tangy, spicy-sweet house dressing, to Zep, a Norristown, Pennsylvania, grinder on a 10-inch roll. In between is a medley of regional (check out the Maine lobster roll, Philly cheese steak and Hoosier tenderloin) and ethnic (carnitas, Cuban mix, souvlaki) treats, plus classics and innovations. This is a road trip to sink your teeth into without paying for the gas.