The Driver was underneath the affect: Proof need to exhibit the driver was impaired, normally by way of a blood Alcoholic beverages focus (BAC) of 0.08% or greater or evidence of drug impairment. Prison rules vary from condition to state, as do prison punishments, but felonies have a significant penalty: https://dui-lawyers.usattorneys.com/presidential-hopeful-rand-pauls-son-busted-for-dui/