Rumble strips. Those rough grooves cut into the surface of the highway to let you know you're drifting toward the shoulder or that there's a stop sign ahead.

Most of the time they're just annoying. But sometimes they play a song.

Back in 2014, National Geographic worked with the state of New Mexico to install singing rumble strips along a portion of Historic Route 66 between Albequerque and Tijeras. When you drive over them at 45 mph it plays America The Beautiful.

Aside from a nice promotional opportunity for National Geographic the singing highway also serves another purpose. It gets drivers to slow down to the posted 45 mph speed limit on this particular stretch of road.

To make the rumble strips sound more like music and less like dinosaur toots engineers placed specially tuned metal plates into the road, then covered them with asphalt and cut the grooves into the surface.

The Singing Road, as it's called, has been around for more than five years but has been making the social media rounds again lately, probably because there's a petition to change the national anthem to America The Beautiful.

If you're a dedicated road warrior, or just curious about the Mother Road, you don't need to go all the way to New Mexico to find it. Historic Route 66 is largely intact from Miami, Oklahoma all the way to Amarillo in the panhandle of Texas. Travel Oklahoma has some good information on where to start your trip and where to see the most interesting roadside attractions.

If you decide to go for a drive along this unique part of American history give yourself plenty of time to stop and explore the shops and roadside attractions along the way.

Dave Diamond

After all, it's not every day you see a giant blue whale in the middle of Oklahoma.