Road art

Today the cracks in our bitumen road are being repaired. I’ve often wondered about those black ribbon marks you see on roads and cycle paths, and now I know where they come from.
 
First you put a strip of black sticky tape along the crack. Then you heat it with a gas jet, so that it melts and runs down into the crack. It hardens as it dries, leaving a sealed crack and a shiny ribbon pattern on the road. Like abstract art on the road.