There’s not much to see on the stretch of Route 66 that connects Albuquerque to the small town of Tijeras, but for one quarter-mile stint, there’s plenty to hear. If drivers obey the speed limit, the road belts out a very special rendition of “America the Beautiful.”
A singing road? Really?
Yes, really. Route 66 became musical two years ago, thanks to meticulously placed rumble strips between mile markers four and five. The tune only works when cars are travelling at exactly 45 mph, giving it the dual purpose of encouraging drivers to stay the speed limit and adding much-needed entertainment to an otherwise monotonous highway.
Matt Kennicott, director of communications for the New Mexico Department of Transportation, told Smithsonian.com how it works. “All of the sounds and music notes that we hear in day-to-day life are just vibrations through the air. For instance, anything that vibrates 330 times in one second will produce an E note—a guitar string, a tuning fork or even a tire,” he said.
To produce an E note with a car, rumble strips had to be placed such that the car would hit 330 strips if driven at 45 mph for one second. “A bit of math tells us this is 2.4 inches between each rumble strip,” continued Kennicott. “After that, it’s a case of breaking down the music into exact chunks of time and applying the same technique to each space depending on what note is needed and for how long.”
The result is a pretty cool real-life Easter egg, which you can see at work in the video above.