6Restriction on driving within a zone
(1)A person may not drive a vehicle on a road within a low emission zone in contravention of the terms of a low emission zone scheme unless—
(a)the vehicle meets the specified emission standard, or
(b)the vehicle is exempt by virtue of subsection (4)(b) or section 17.
(2)Where a person drives a vehicle on a road within a low emission zone in contravention of subsection (1), a penalty charge is payable in respect of the contravention.
(3)But, despite subsection (2), if—
(a)the same vehicle is driven within the same low emission zone in contravention of subsection (1) on more than one occasion in the course of the same day, and
(b)the person to whom the penalty charge notice would be issued in respect of those contraventions is the same person,
only one penalty charge is payable in respect of the contraventions.
(4)The Scottish Ministers may by regulations, following consultation with such persons as they consider appropriate—
(a)make provision for or in connection with the specification of the emission standard for the purpose of subsection (1)(a),
(b)specify vehicles or types of vehicle which are exempt for the purpose of subsection (1)(b) including, in particular, by reference to their construction or use,
(c)make provision for or in connection with the amount that may be imposed as a penalty charge under subsection (2) (which may include provision for discounts and surcharges).