A Japanese engineer by the name of Shizuo Shinoda was digging with a bulldozer when he accidentally scraped some markings into a road with its claw. Later when he drove over the markings he realized that the vibration produced in his car can be heard as a tune. In 2007, a team of engineers from the Hokkaido Industrial Research Institute refined Shinoda's designs and built a number of “melody roads” in Japan. These roads have groves cut at very specific intervals along the road surface. Depending on how far apart the grooves are and how deep they are, a car moving over them will produce a series of high or low notes, enabling designers to create a distinct tune. The closer the grooves are, the higher the pitch of the sound. The critical ingredient in the mix is the speed of the car.

The Civic Musical Road in Lancaster, California. Photo credit: roadtrippers.com

There are four melody roads in Japan, one each in Hokkaido, Wakayama, Shizuoka and Gunma. They all play different tunes. They stretch between 175 to 250 meters, and are carved with thousands of groves. Aside from street signs, the roads are marked by colored musical notes painted on the surface of the road which alert motorists of the incoming musical interlude. The grooves are laid down on the side of the road near the curb and not in the middle, so drivers have the option to either go over them or avoid them. In order to hear the tunes, they need to keep the car windows closed and drive at 28mph keeping one wheel over the grooves . Drive too fast and it will sound like a tape on fast forward. Drive too slow and it will have the opposite effect.

The first musical road, however, was not Japanese. It was created in Gylling, Denmark, by two Danish artists Steen Krarup Jensen and Jakob Freud-Magnus, in October 1995. Called the Asphaltophone, the street is made from a series of raised pavement markers, spaced out at intermittent intervals so that as a vehicle drives over the markers, the vibrations caused by the wheels can be heard inside the car.

Grooves on a melody road in Japan. Photo credit: Yusuke Japan Blog

The idea of musical roads has caught engineers in several other countries. There is one “Singing Road” in South Korea close to Anyang in Gyeonggi. It plays the nursery rhyme "Mary Had a Little Lamb". Unlike other melody roads, it was designed not to draw tourists but to help motorists stay alert and awake. The Singing Road is located on a particularly treacherous section of a highway where lots of accidents occur due to dozing and speeding. 68% of traffic accidents in South Korea are due to inattentive, sleeping or speeding drivers.

America got its first melody road in 2008. It was originally built on Avenue K in Lancaster, California, for a Honda commercial. The Civic Musical Road, named after Honda Civic, stretches for a quarter-mile and plays back a part of the Finale of the ‘William Tell Overture’. But the intervals are so far off that the melody bears only a slight resemblance to the original tune. Later, when residents complained that the grooves produced too much noise from nocturnal drivers, they relocated the strip to Avenue G.

Another musical road is located in the village of Tijeras, in New Mexico. Driving over the grooves at 45mph causes the car to play the famous song "America the Beautiful". The project was funded by the National Geographic Society, and overseen by the New Mexico Department of Transportation who said that the real motive behind the musical road is to get drivers to slow down.

Grooves on the musical road in Tijeras, in New Mexico. Photo credit: drivenfordrives.wordpress.com

A sign ahead of the Civic Musical Road in Lancaster, California. Photo credit: roadtrippers.com

The Civic Musical Road in Lancaster, California. Photo credit: roadtrippers.com

Photo credit: Yusuke Japan Blog

The musical road in New Mexico.

The Singing Road of Anyang, South Korea

The Melody Road in Japan.

Sources: Wikipedia / The Guardian / ABC News