“(1) OFF-HIGHWAY VEHICLE.—The term ‘off-highway vehicle’ shall be defined by the State in which the applicable System unit is located, in accordance with the law of the State.

“(2) ROAD.—The term ‘road’ means the main-traveled surface of a roadway open to motor vehicles that is owned, controlled, or otherwise administered by the Service.

“(b) Applicable law.—The law of the State in which a System unit is located shall apply to the use of motor vehicles (including off-highway vehicles) on roads within a System unit.

“(c) Violations.—Violating a provision of State law applicable to a System unit under subsection (b) shall be prohibited in the applicable System unit.”.

“(1) OFF-HIGHWAY VEHICLE.—The term ‘off-highway vehicle’ shall be defined by the State in which the applicable System unit is located, in accordance with the law of the State.

“(2) ROAD.—The term ‘road’ means the main-traveled surface of a roadway open to motor vehicles that is owned, controlled, or otherwise administered by the Service.

“(b) Applicable law.—The law of the State in which a System unit is located shall apply to the use of motor vehicles (including off-highway vehicles) on roads within a System unit.

“(c) Violations.—Violating a provision of State law applicable to a System unit under subsection (b) shall be prohibited in the applicable System unit.”.