The motive force was beneath the impact: Evidence have to present the driver was impaired, typically via a blood Alcoholic beverages concentration (BAC) of 0.08% or greater or proof of drug impairment. Criminal legal guidelines vary from state to condition, as do legal punishments, but felonies have a large penalty: https://dui-lawyers.usattorneys.com/drunken-driving-accident-on-interstate-75-woman-from-fort-myers-in-custody/