US Route 40 grew out of the old National Road in 1926 to become one of the nation’s first transcontinental highways, stretching from Atlantic City to San Francisco and helping revive the road in the automobile age. As cars and trucks became common in the 1920s, paved all-weather highways and roadside services transformed travel, and gas stations, diners, and motels brought new opportunities and prosperity along the route. Handsomely designed service stations rose beside the highway to provide fuel and routine car care, making long-distance travel more comfortable and dependable. Until Interstate 70 was completed in the 1970s, US 40 remained one of the country’s primary east-west routes. The National Road continued to be recognized for its importance, and in 2002 the Historic National Road from Maryland to Illinois was designated an All-American Road.