I wonder about the breakdown of pothole causes. Yes, Nature's way will cause potholes and they will naturally expand if not rectified.

But then I think about the construction crew down the street from me, in Philadelphia, that didn't properly fill in and tamp down the trench they dug for a new sewer line. "Just fill it with some stones and dirt, and throw some Home Depot black top down on it," the foreman said, I imagine.

The thing grew, and became a gargantuan pothole. Eventually the city fixed it, and granted this probably has everything to do with the contractor in question, and I've seen larger construction companies doing things right, but I'm convinced we could eliminate a lot of potholes if crews just did the job right.