Over time a gravel road used by heavy vehicles will deform. The weight of cars and trucks will crush rock into smaller bits as they also push gravel to the outer sides of the road forming raised areas in the center of the road as well as raised shoulders. As the tire tracks slowly deepen, gravel being broken into smaller bits water begins to do more damage.
Add to the scenario a hill that sheds water to the road and a creek that floods and now you've also got extra erosion as water channels down along the tire tracks in the road.
In recent years I've watched as flooding due to more frequent 7-8" rain events do more damage to our private road each time. It's a project I should have taken on sooner. I don't have a tractor so all this will be done by hand using a few tools. It's a lot of work but I consider it my daily exercise. Though the final result will take much longer to accomplish it will be done just as well and with zero carbon emissions. And I'll be healthier for the exercise.
Broken down into 1.5 to 2 hours per day this section of road will take me 5 to 7 days, 10-13 hours. The photo above was taken after about 3 hours of work. Each workout has my heart rate average at about 140bpm which is equivalent to a moderate effort bike ride on the trail. Perfect.
The general idea is to cut into the shoulder and rake the top 3-4 inches of dirt and gravel back onto the road. It's messy but will all settle in. I'm only doing the low side of the road where water needs to shed to. With 5 inches taken off the top of the shoulder and added to the road, water will now shed properly off the road and into the lower elevation of the woodland moving away from the road (to the left side of the photo).
Once I get the dirt pulled onto the road for the full length of the area, I'll then spend a few hours raking it, mixing the gravel and dirt and leveling out any obvious bumps. I'll also make a bit of effort to break the center hump down a bit. Normally a raised crown on a gravel road is desirable but in this section of road I only have drainage on one side, hill on the other, and I want to have a nearly level road with just a very shallow angle off the downslope.
I've already completed one other section of road and there will be another two sections to do after this one. When it's all done it will amount to 4 sections, each about 50 feet, each about 5-7 days of work. So, a month of great exercise and when it's completed an improved road that will be more resilient, less likely to erode and loose gravel with each heavy rain.
Side note, while I walk and ride a bike on this road daily, I rarely actually drive a car. Most of the large vehicle traffic is family that visit.