It'd be interesting to try charging vehicles relative to the road damage they do as it's proportional to around the fourth power of weight. It would likely change the nature of logistics as it could mean that large trucks would be more expensive that using two or three smaller trucks. Similarly, buses would benefit from being smaller and lighter.
Okay, so there is a maximum. Charging proportionate to the road damage costs would still change the cost benefits of using single large vehicles vs multiple smaller vehicles, or possibly lots more axles.
