Musical road trip, anyone? There are four roads in Japan that play melodious music when you drive over them, but the idea is much more interesting and inspiring. These roads are in Hokkaido, Wakayama, Shizuoka and Gunma regions of Japan, and all play different tunes. Japanese locals call them Melody Roads as these musical paths play music for drivers. Stretching between 175 m to 250 m, these roads are carved with thousands of grooves that make music when you drive across. These grooves are cut at specific intervals, and driving over them at a particular speed creates soothing music. But these roads are more than just a fun diversion. Do you have any idea what that could be?

The roads work as a speeding alert sign, along with keeping drivers awake while driving. Besides road signs, all the roads are marked by musical notes that are painted on the surface of the road. These signs alert motorists of the incoming musical tune. Since these grooves are set on the side of the road and not in the middle, drivers have the option to either go over them or completely avoid them. To listen to the musical notes, motorists need to keep the car windows closed and drive at 28 m/hr, keeping one wheel of the vehicle over the grooves. If you drive too fast over it, the sound will come out as a tape on fast forward but if you go slow, there will be music. Do you think this is a good idea?

The first musical road, however, was not Japanese. It was created in Denmark, by two Danish artists 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. Have you ever driven on this road?

There are several other musical roads throughout the world. Which of these have you ever driven on?