According to The Guardian:
"A team from the Hokkaido Industrial Research Institute has built a number of "melody roads", which use cars as tuning forks to play music as they travel.
The concept works by using grooves, which are cut at very specific intervals in the road surface. Just as travelling over small speed bumps or road markings can emit a rumbling tone throughout a vehicle, the melody road uses the spaces between to create different notes.
Depending on how far apart the grooves are, a car moving over them will produce a series of high or low notes, enabling cunning designers to create a distinct tune."
This looks like a great opportunity for jingle writers!