As if your car stereo pumping out mad J-Pop tunes is not quite enough to keep you entertained and awake while driving to your favorite Gunma tourist destination, Japanese engineers have designed numerous melody roads that consist of strategically spaced grooves in the road that rumble often unfamiliar tunes through your car, similar to the rumble strips you might be familiar with back home.
The idea of a melody road came upon Mr. Shizuo Shinoda; a bulldozer driver who accidentally carved some grooves in a road and discovered that when driving over them, the vibration of the tires creates a rumbling noise that can be heard within the cabin of a car.
In 2004, the Hokkaido National Industrial Research Institute in Sapporo took Mr. Shinoda’s brilliant idea and ran with it. Scientists created melody roads from strategically placed grooves in the concrete. The secret is in the spacing of the grooves; grooves spaced farther apart create lower pitched sounds, whereas closely spaced grooves create high pitched sounds. Placing the different pitched tones together can create a melody. The rhythm of the song is created from the length of the grooves.
Gunma has six such melody roads within it’s boarders and most are easily accessible along the tourist routes.
Kusatsu: R292 has a 300m long rendition of 草津節 (Kusatsu Song) located on the mountain road approaching the town. View Map
Tsumagoi: Located on R94. 雪山讃歌 (Snowy Mountain Song of Praise). View Map
Mt. Haruna: Located on R33 on the road up to the lake. 静香な湖畔 (Quiet Lake). View Map
Maebashi: Located on R353. チューリップ (Tulip). View Map
Numata: Located just off R120 on the Tone Boukyou Line (Shirasawa). 夏の思い出 (Summer Memories). View Map
Optimal driving speed over melody roads is a whopping 28 km/h. Be sure to keep your windows rolled up for the best possible sound.
More information is available on Wikipedia. Please let me know if my locations are slightly off and I will do my best to fix them.