No matter haw nice a job U will do those delivery trucks will find any weak spots.
Do prepare a "rough" roadway but wait 'til the project is almost over B4planning any finish work.
Coarse rock in any soft areas (let delivery vehicles compact it) th finer stone if needed for traction on slopes.
As time and work goes by you'll decide what and where more stone/gravel is needed.
Trying to be perfect from start will be $$'s and still need corrections.
\Besides delivery trucks will provide free compaction.