What kind of glue does road department use for reflectors in the road and where can it be bought?

Answer 1

It's called Quik Dots. You get a roll of asphalt tape with a protective covering on both sides. They cut it into squares, stick one on the back of each marker, take the markers to the road, peel off the other cover and stick the marker to the road. The first hot day melts the asphalt, and makes the marker bond permanently. You get it from the same company that sells the reflectors.