10 CFR § 490.3 - Excluded vehicles.
When counting light duty motor vehicles to determine under this part whether a person has a fleet or to calculate alternative fueled vehicle acquisition requirements, the following vehicles are excluded -
(a) Motor vehicles held for lease or rental to the general public, including vehicles that are owned or controlled primarily for the purpose of short-term rental or extended-term leasing, without a driver, pursuant to a contract;
(c) Motor vehicles used for motor vehicle manufacturer product evaluations or tests, including but not limited to, light duty motor vehicles owned or held by a university research department, independent testing laboratory, or other such evaluation facility, solely for the purpose of evaluating the performance of such vehicle for engineering, research and development or quality control reasons;
(d) Law enforcement vehicles;
(e) Emergency motor vehicles, including vehicles directly used in the emergency repair of transmission lines and in the restoration of electricity service following power outages, as determined by DOE;
(g) Nonroad vehicles; and
(h) Motor vehicles which, when not in use, are normally parked at the personal residences of the individuals that usually operate them, rather than at a central refueling, maintenance, or business location.