Is the current road path dry, packed, and stable? Any muddy or soft spots?
I was prepared to lay a bed of rail ballast or #3 for our entire roadway and then top with crusher run (3/4 minus here). The guy doing the initial work suggested only using #3 where the ground was obviously soft or had issues. Four years later, and it looks like he was right. Everything is rock solid and has held up very well to construction traffic and follow-on use (had a cement truck out once each of the following years and no further compaction). I think there was only one small spot where I added more #3.
One thing I did do was put down another layer of crusher run about 8 months after we moved in, as a final smoothing/grading. I am sure that helped, and I think it was smart to wait to give everything time to settle.
I think heavier equipment is needed for spreading large amounts of ballast or #3 (small areas can be done with a box blade with surprisingly good results). For crusher run however, a tractor and box blade is all you need -- provided you can get the truck operator to spread the crusher run on delivery. They can get it about 85% good, and then you follow up with a box blade to finalize things. Both times I have put down crusher run, the results achieved with tractor and box blade were very good and impressive.
If you don't have a lot of experience with a box blade, read up here -- lots of good topics. Angle of attack and angle/bite of the rear cutting edges is the key. Hydraulic top link also key. If the delivery truck can lay down the crusher run, you'll then go over it with a tractor with the box blade angled up in front so that the rear cutting edge is feathered and doing more smoothing than digging. The box blade needs to be all the way down (floating the 3-pt hitch) so that any up/down motions of the tractor axles do not create dips and bumps. A land plane or grader box implement is going to do the same thing but with a much longer frame to eliminate the dip/bump problem even further and smooth even better. While a box blade can actually move material (removing high spots and then depositing the material in low spots) a land plane is more about grading and smoothing and not as capable of moving material. Either will work for your application, but consider long term needs/use to decide which is a better option.
We cut our crown into the original dirt road bed with a dozer and used an excavator to dig the ditches (1-2' deep). For anything more than a shallow ditch, an excavator is the best tool for the job by far. Later on, you can fine tune or re-grade the crown with tractor and box blade on the crusher run top layer. And you can always tweak the ditches with tractor and angled and offset rear blade, or with an angled box blade if it's wide enough (most are not).