; driving under the influence The terms driving while intoxicated and driving under the influence mean driving or being in actual physical control of a motor vehicle in a State while having a blood alcohol concentration that is greater than or equal to the lesser of— (A) the blood alcohol concentration limit of the State in which the individual is driving; or (B) 0.08 percent. (3) Ignition interlock device The term ignition interlock device means an in-vehicle device that— (A) requires a driver to provide a breath sample prior to the motor vehicle starting; and (B) prevents a motor vehicle from starting if the alcohol concentration of the driver is above the legal limit. (4) Motor vehicle (A) In general The term motor vehicle means a vehicle driven or drawn by mechanical power and manufactured primarily for use on public highways. (B) Exclusions The term motor vehicle does not include— (i) a vehicle operated solely on a rail line