Tar printer

Back in 2004, Bikes Against Bush created a mobile bicycle-based chalk printer to print messages on sidewalks. The bike had a large dot-matrix printer on the back, designed to print messages as the bike rolled along sidewalks.

When cars drive over roads, any grooves or bumps can vibrate the tires at a desired frequency, depending on the car's speed and the spacing between bumps. You might recall the safety grooves etched in the sides of highways, or near intersections that warn for an approaching decrease in speed.

In japan, the 'singing roads' project encoded songs into the roads. likewise, the 'road tunes' HB idea records roads as grooves.

However, these require expensive grinding equipment, and the grooves are relatively permanent. A printer that applies tar or fast-curing epoxy to the road surface in a similar pattern could print song messages or maybe even crude speech reconstructions more cheaply, instead of cutting material out of the road surface.