A pesky sprig of wildflowers grows through the asphalt on the side of the old Route 66. The legendary road that stretched from Chicago to Los Angeles became a relic in 1984 when the last stretch of Interstate 40, the high-speed east-west highway, was completed just outside Williams, Arizona.

(Text adapted from, and photograph shot on assignment for, but not published in, "Romancing the Road," September 1997, National Geographic magazine)