How I finally stopped the potholes in my RAP driveway

This tracks with my driveway too. Mine is about 400 feet of RAP over clay, and the worst pothole always showed up in the same bend where the yard drains across. I spent two springs dumping more RAP in it before I finally dug down about 8 inches and realized I was basicly making a RAP soup over mud. Filled it with some 57 stone a neighbor had leftover from a septic job, tamped it with the back of a digging bar because I didn't own a compactor, then capped it with the fines that had raked off to the side. Two winters later and that spot has held. The wet weather trick is real. I did my walk-around during a drizzle with a cup of coffee and it told me more than a year of patching did. Water was coming off the mower shed roof, across the grass, and straight onto that bend. A cheap gutter extension on one downspout moved the water 10 feet further out and things improved before I ever touched the drive again.

One thing I'd add is that the tire-packing method works better than people expect if you're patient. My wife thought I was nuts parking the F-150 in the same two tracks every night, but that section got hard as concrete by the end of the summer. Also, if your RAP has alot of big chunky pieces in it, save the finer stuff for the top layer or you'll be picking rocks out of your tires.

The concept of subsurface wicking is something I've encountered repeatedly with high-volume traffic areas, where even if the surface grading seems adequate, hydrostatic pressure from the surrounding grade can push moisture into the aggregate base itself, effectively turning the fines into a saturated sludge. I once noticed that my worst spots weren't where water was pooling visibly, but precisely where the soil beneath the RAP appeared slightly darker even after drying, indicating capillary action was drawing dampness upward through the lower layer. This suggests that merely fixing a visible low spot is insufficient if the underlying perimeter drainage is completley compromised, requiring attention to grade transition over a much broader area.

Timing matters more than I thougth when I first started messing with mine. Made the mistake of patching holes in early April when the ground was still soggy underneath, and every one of those patches failed. Now I wait for a dry stretch in late summer, dig, fill, and let the truck do the compacting. Held up way better.

Also had decent luck laying down some cheap landscape fabric under the worst 30 foot stretch before I dumped fresh RAP on it. Kept the mud from pumping up through the stone. Curious if anyone else has tried fabric under RAP or if it just turns into a shredded mess after a few years of plowing.

First time posting here, been reading for a few weeks. My setup is a little diferent, crushed limestone over sandy ground, so I never get that soupy mud under the holes, more like the material just walks outward with every car. Same spot near the mailbox every year though. Does the dig-out-and-fill method still apply when the base itself is draining fine, or is that more of a spread-the-load situation where I should just be adding more of the bigger stuff on top? Not sure if sandy soil changes the whole approach or just means I got lucky with drainage.