In the 1920s, rising automobile traffic on the National Road helped diners spread as America's first fast-food restaurants, serving long-distance travelers with quick, friendly, reliable, around-the-clock meals and helping create a new food culture shaped by location, ample parking, bright neon signs, and drive-in convenience. Visible, accessible, and familiar, the diner became one of the first recognizable roadside building types, with stainless steel, broad windows, and neon signs drawing motorists along major highways such as US 40, where theaters, motor courts, shopping centers, malls, and fast-food restaurants also reshaped the roadside landscape. The automobile revived the National Road in the 1920s as paved, all-weather highways and the 1926 federal numbering system turned it into US Route 40, a transcontinental route from Atlantic City, NJ, to San Francisco, CA, bringing new prosperity through gas stations, diners, and motels and making it one of the country's primary east-west roads until Interstate 70 was completed in the 1970s. Soon after the turn of the 20th century, Americans exchanged horses, carts, and interurban rail cars for automobiles, old roads like the National Road were paved, new traveler services appeared, and a modern transportation era began. The road continued to play a significant role in the development of the United States, and in 2002 the US Secretary of Transportation designated the Historic National Road from Maryland to Illinois an All-American Road while Indiana worked to preserve its section and historic corridor. Along this road, the restored 1841 Huddleston Farmhouse in Cambridge City still welcomes visitors, and Indiana's H&C Studebaker blacksmith shop, which became the Studebaker Manufacturing Company in 1868, grew into the world's largest wagon manufacturer before introducing an electric car in 1902 and a gasoline-powered car in 1904, successfully moving from horse-drawn to gasoline-powered vehicles.