Big trucks are subsidized for the reason that they bring products to market that would otherwise be unable to be economically transported. So, you’d need a sep

Big trucks are subsidized for the reason that they bring products to market that would otherwise be unable to be economically transported. So, you’d need a separate tariff for the big trucks, but you should tax them based on weight per axle. Smaller vehicles could easily be taxed by weight per axle, which is the important factor for road damage. Just make sure that you’re fairly taxing all smaller vehicles equally, and not intentionally making it harder for EVs.