the fundamental of building a road with a specific grade/angle, is really simple, and can be done with a bubble level, and a simple wedge that is cut to the angle/degree you want your road to be, and Marty demonstrates!

 

I get a kick out of simple engineering, as, in my opinion, REAL engineering can be accomplished using the original simple fundamentals of levels, wedges levers, etc. 

Plus, I love the surveying stuff