15. Any person who uses or keeps on any road any vehicle for which a licence is not in force, not being a vehicle exempted from tax under this Act by virtue of the provisions of any written law, shall be guilty of an offence and —
shall be liable on conviction to a fine not exceeding $2,000; or
if it has been proved to the satisfaction of the court that he had the intention to evade payment of any tax chargeable under this Act, shall be punished on conviction with a fine of an amount equal to 3 times the tax payable —
if a vehicle licence had been taken out for the period, beginning with the expiry of the vehicle licence last in force for the vehicle before the date of the offence; or
if there has not at any time before that date a vehicle licence in force for the vehicle, beginning with the first day of the month in which the vehicle was first kept by that person,
and ending with the last day of the month during which the offence was committed.