When all lanes are figured in, it adds up to over 614 lane miles. That means if every traffic lane was linked in a straight line, a person could drive to Los Angles and back without covering all the lane miles in Salinas. This equates out to over 56 million square feet of asphalt and concrete. Road pavement, especially asphalt, is a flexible material, built on compacted sub-soils, providing a hard, and relatively smooth, surface for vehicles to drive on. As pavement gets older it loses some of its flexibility and tends to become brittle.
Small cracks start to form as the traffic load beats on the pavement each day.
If water gets into these cracks, it tends to soak through to the underlying compacted base-soil, turning it to soft mud. Once softened, the wet soil can then be squeezed to the sides as heavy traffic flexes the pavement downward producing a soft spot under the road surface. Eventually, the pavement breaks and tires knock the pieces out of the newly created hole. It is this wet and weakened ground structure under the pavement that is the cause of the majority of the potholes seen throughout the City. This is why so many new potholes appear during or right after the rainy season.