I was fortunate to observe municipal gravel road maintenance in my youth.
I duplicated their rig when we built our 3 mile cottage access road.
The rig consisted of 3 blades set up as an 8 ft square rig.
Commonly referred to as a 'drag'.
3 'blades' did all the work.
Our first rig was made from 6" X 6" timbers with 3/8" steed flats lag bolted as cutting edges.
Front and rear blades were perpendicular to the road bed while the center was at an angle.
Front blade would chop the high spots, 2 nd (angled blade) would move material sideways and fill in the dips and the rear blade smooth the roadbed.
2 chains from front 'drag' corners went to the outside ends of an old Willis Jeep.
2 passes would leave our road bed looking like a freshly paved road bed.
Later the city did the grading with a huge grader but it never did a better job than we did with our DIY drag.
The drag would ride up and over big imbedded rocks while the big grader would catch and snag on them occasionally tearing them out.
If it simply 'snagged' it would then leave a blade width hump while our drag spread the material nicely.
U need 3 blades for it to work.
2 serve as a reference 'base' while the third provides the cutting action.
Sort of averaging it out.
LOL, while posting this AIRBISKIT was also posting.
His 3rd photo is very similar to the drag I was describing.
But as U see a simple 'drag' really works wonders.
Last drag I made I added a flat surface to mount additional weigh for more aggressive action.
If a road surface was very compact U could even add teeth to the front blade.
