We had some stretches of Interstate and Interstate quality roads in the DC suburbs that showed up a couple of weeks ago with cave-in strips between main lanes. One of those events happened near us on our way home from IKEA in Woodbridge VA. There were about 20 cars pulled over to the side of the highway waiting for the insurance examiners to check 'em out. At the same time VDOT had a contractor on the spot digging out the broken pavement and putting in new asphalt. That strip was a good 100 feet long.
That's why I wouldn't worry too much about cracks in pavement ~ YET.
Best to get the county out there fixing the pavement.
Interesting.
Thanks for an encouraging reality check.