3D custom map for Assetto Corsa

I am trying to get some practice for my driver's license and I need someone to model the driving course I will take the est on. I will then import the model to Assetto Corsa, I know from blender works fine if exported with png textures... the reason I am not doing it myself is because I need the dimensions to be as they are in real life, the meassurments can be taken from google maps. there is also a problem from the google maps view and is that the satellite view was taken while the course was under construction. I have the full map layout so, some photoshop of sorts will be needed to "draw" the rest of the course... I'm attaching the aerial view from maps and the layout of the rest of the course...