There could be a number of reasons as to why your driveway is uneven, cracking, or sinking in certain areas. In a climate like that found in Johnstown, with the kind of loam-based soil that this area of Pennsylvania has, however, it is very likely that soil washout or saturation are contributing to the issues that you see around your property. Alternatively, there is a chance that your driveway is dealing with defects and flaws within the concrete used to construct it.
Loam-based soil is incredibly fertile and generally more stable than clay-based or sandy soils, but it is also lighter and slightly less cohesive. This means that when its natural drainage capabilities are overwhelmed or the weather is extreme it can shift, lose strength, or even wash away altogether. This will lead to many issues for any structure reliant upon it, the most common of which are sinking and fragmentation.
Defects in the concrete used to make your driveway are far less likely than you might expect, but they could be an underlying cause or contributing factor. This can occur for a number of reasons. First, there can be issues with the materials used to make the concrete, or the proportion of materials used to make the concrete. Secondly, there could be issues in the curing process. Wherever the issue starts, concrete that is fundamentally flawed is more at risk of structural and cosmetic damage on all fronts. Unlike soil-based issues that can be mitigated, however, flawed concrete may need to be replaced entirely.