Water collects in a low spot
Vehicle tires displace wet, loose aggregate and deepen the depression. If the low spot is filled without restoring drainage, the next rain and traffic cycle can reopen it.
The driveway has lost its crown or cross-slope
A deliberate crown or cross-slope helps water leave the travel surface. The right shape depends on driveway width, terrain, entrances and available drainage routes.
The base is weak
Soft subgrade or inadequate base material can allow the surface to flex and rut. Some areas may need failed material removed and rebuilt with suitable structural aggregate before the finish layer is placed.
Loose material was not properly worked
Simply dumping stone into a hole does not integrate it with the surrounding drive. Repair commonly involves loosening or removing failed material, reshaping, placing appropriate aggregate and controlled compaction.
Runoff crosses the drive
Water entering from an uphill yard, ditch or downspout can cut channels and carry fine material away. Drainage improvements may need to happen before or alongside surface repair.
Traffic is concentrated in one path
Turning, braking and heavy vehicles place more stress on specific areas. Material depth, driveway width and surface shape should reflect how the property is actually used.