[Retric]

It doesn’t help that much. Each tire of a fully loaded 18 wheeler carries 4.4x the weight of a typical car tire. 4.4 ^ 4 = 378x the damage per tire but there are also 4.5x the tires so your at 1,700x the damage.

That’s an oversimplification, but it doesn’t really matter if it’s 99.9% or 95% of the damage ware is still absolutely dominated by heavy vehicles.

[ncruces]

And how many more SUVs go through that road? If there's a few hundred SUVs for every 18 wheeler, it's no longer negligible: it's 10 or 30% of the damage.

And it could be a lot more negligible, if that mostly drive alone, drove a car with half the weight.

[Retric]

Most SUV’s aren’t that heavy.

I used 4,000lb for the car, a 2024 Chevrolet Suburban which is huge only clocks in at a 5,824 lbs. Load another 1,000lb for passengers etc and (6,824/4000) ^ 4 = 8.5x a car or 0.5% what I calculated for a full 18 wheeler.

Sure there’s more cars than 18 wheelers but 7,000lb is a rather extreme outlier in terms of SUV weight.

[ncruces]

Well, my 7 seater has a kerb weight of 2780 lbs (and it's a hybrid, the petrol is lighter); fully loaded it's under 4400 lbs.

And it's probably heavier than most cars around here, because most cars are not 7 seaters, but 4/5 seat hatches.

US SUVs and pickup trucks wouldn't fit most parking lots around here (to tall, to wide to even get in), but somehow the problem is never the size/weight of cars people got used to drive.

[gruez]

That statement is only true in aggregate. If you you're taxing individual vehicle owners SUVs will still get taxed way less than trucks.