You can ratchet up the tax on heavy trucks because "muh road wear" but then you'll have a world where everything is delivered in small trucks and there will be problems with that. At the end of the day it comes down to a subjective question of which problems get which priority.
Let's dream for a moment where the tort system worked perfectly. All environmental externalities would be perfectly priced by class actions. Cause $100,000 of lung damage, pay $100,000 to the survivors. If only such efficient courts existed...
So then tax those problems until taxes represent the true societal cost of things
Is that really a bad thing? If shipping via big trucks (compared to small trucks) causes $200 more road wear per year, but saves $100/yr in gas (and other expenses), why shouldn't we use small trucks?
> At the end of the day it comes down to a subjective question of which problems get which priority.
You're right, there will be some subjectivity involved, but at least the general goal is trying to be as neutral as possible. It's not unlike cap & trade for dealing with climate change - letting the market decide what's the most cost effective way.
Why the focus on small trucks as if they're a panacea?
Right, but isn't the whole premise that the damage is the truck's weight cubed (or ^4)? Splitting large trucks to small trucks only increase wear linearly.
>Why the focus on small trucks as if they're a panacea?
I'm not. It's a hypothetical.