That hole has been most likely been caused by a water pipe bursting and washing away the soil around the pipe .. but if you knew the number of potential sinkholes, caused by unstable geology, abandoned unknown mines, and oil extraction .. you'd never drive on any U.S. road or highway.
http://www.tfhrc.gov/pubrds/julaug99/minehole.htm
http://www.fhwa.dot.gov/mine/kansas02.htm