I totally agree about the LACK of good road grading abilities....yes, I have run a road grader on our private ranch roads....and NO...I didn't have ridges, corduroy, or a FLAT road surface. (It takes effort and time, but YES, corduroy areas can be cut out of a road. Road surfaces need to be crowned in order to shed off water.) Experience was my teacher....along with my dad and a former Custer County Commissioner.
I have been told by the Custer County Road Dept. in the past few years, 'you can't get rid of the corduroy'....or 'it's too expensive to do anything more than a bandaid fix on the county roads'.