Sub-surface water may, by erosion or freezing and melting, cause cracks and breaks in roadways. Pits and grooves in road surfaces are the first signs of highway degradation. These may form as holes deep enough to trap a tyre and cause an axle to break. If left unrepaired, small fissures can allow water to erode the foundation of a road, and before long the entire road will require reconstruction. Roads in developing countries, and in heavily trafficked major urban areas in developed countries, tend to be subject to insufficient road maintenance which permit rutted and pitted surfaces and dangerously deep pot-holes to develop. A road surface can last thirty years with proper maintenance.
When road authorities are not able to afford maintenance work, the costs passed on to road users are larger than the "savings" in public expenditure. Over the life of a road, the total operating costs of vehicles are typically four to ten times the costs of road construction and maintenance. Since operating costs may easily double on poorly maintained roads, the economic loss is considerable.