Lol... First they came for the people doing 20 over, and I don't drive 20 over, so I said nothing. Then they came for the ones doing 15 over, and I don't do 15 over, so I said nothing...
You're talking about applying fees and profits to people deemed "less safe" by some arbitrary measurement, and assuming that said fees and profits will never be applied to you because you meet what will be the likely initial standard, but you're assuming the arbitrary measurement will remain fixed... And it absolutely will not.
The thing is, the revenue you're suggesting as an incentive to avoid those behaviors will become a documented and budgeted source of revenue for someone, somewhere, and if your pie in the sky works, and said revenue reduces because the roads get safer, the people who've budgeted that revenue will be incentivised to tighten the restrictions to regain the revenue loss, all in the name of safety, of course...
Of course, you have nothing to worry about if you're willing to comply with the increasingly restricting goalposts...