A driveway that's constantly muddy or rutted almost never gets fixed by just dumping more gravel on top — the problem is usually underneath.
The real causes
Most muddy driveways trace back to one of two things: an inadequate base that lets vehicle weight push gravel down into soft clay underneath, or poor drainage that leaves water sitting on or under the driveway surface instead of running off. Sometimes it's both.
Adding gravel on top of a bad base treats the symptom temporarily — it looks better for a while, then the same ruts reappear as the new gravel gets pushed into the same soft ground.
What actually fixes it
A real fix usually means regrading the driveway with proper crown or slope for drainage, and rebuilding the base with appropriate material rather than just topping off what's there. In some cases, adding a culvert or correcting a low spot that's collecting water is what actually solves the problem.
We evaluate the underlying cause during a site visit rather than just quoting a load of gravel.