What I would blog about if I were six

Answers to questions only I was asking Part III: How do road work crews cut those very thin, deep (6-12 inches, I would) lines in asphalt to section off one area where they're going to dig? They shoot a “blade” of really high pressure water into the road. I tried to find a picture of the machine used, but all I can really find are a couple of .pdfs on the topic. Yes, this whole post is because I saw a work crew using the machine earlier today and it looked really cool.