Let's leave the specific numbers aside and just assume that there's a huge gap, e.g. ~$10 to ~$30k. You still haven't explained why that "doesn't work".
Clearly it would make some truck operations uneconomical, but that's a feature. The assumption is that the cost is being paid today, but it's effectively a subsidy that society is paying for.
Even if someone's going to argue that trucking is so critical to society that the trucks can't pay their fair share of road maintenance this way of doing it still seems dumb.
If you're paying ~$30k/yr for road maintenance per truck I'm willing to bet that you could e.g. spend ~$10k/yr to retrofit the truck to be gentler on the road (e.g. just adding an extra axle), and then use the remaining money to more directly subsidize trucking.
