Road work- how do they get the yellow paint off of the road without ripping up the cement?

I always wondered how road construction workers managed to change the markings on the roads and get rid of old yellow and white lines without tearing out the cement. Maybe they do tear it up and I just never saw that part....does anyone know?Road work- how do they get the yellow paint off of the road without ripping up the cement?
With a special machine, like a floor sander, but especially made to scrub up the yellow paint and suction up the paint and cement that is dislodged. Then new strips can be repainted where needed.Road work- how do they get the yellow paint off of the road without ripping up the cement?
They sand blast it!

antispyware