Well I decided to get something close to real world scale for my fly overs and this is what I got.
There are 2 maps in the .rar file, one for use masking the road positive and nevative, and the other as a population mask. In my render the truck is 33 feet long and the wheat I got I think from terragen.org and is scaled .2,.2,.2, the impala is also real world scale.
to get the roads to be 1 mile apart to need to scale the maps to 10700 x 12224. Then you get 2 lane NorthSouth roads and I think 4 lane EastWest roads as well.
I also used the default terrain and restricted all the action to Simple Shape Shader 01 with a base of the camoflage preset.
added a top down view. The little white markis the semi trailer