1 concrete for 4 asphalt? This might be somewhat cheap, or? For a 2 km long 4 metre wide road 4000 bricks are needed, or 2400 if the needed amount is reduced to three units. Would this be still too much? Concrete is widely used as a base foundation, roads on the other hand account only for a small fraction of the paved surface.
For the placement of line marking within a road i strongly recommend the use of blueprints. Just put a few robo ports into your armour and let your drones do the job. With this method it is possible to construct kilometres of roads within a half of an hour, all with different marking or hazard tiles.