Passenger car road taxes are an immense subsidy of road freight.

… and this is why price comparisons between rail and truck freight are typically bad, my dad tells me: because railways are expected to pay for their tracks, whereas trucks’ use of the road network is massively subsidised by passenger cars.

I think there's a lot of truth in that. That why I was so specific about including weight as a factor.

But you still need to maintain existing and build new roads, and not only trucks drive on the road. What about snow? It needs to be removed for normal cars as well as trucks.

Snow removal is probably different, but the point is that road maintenance due to regular road wear would be significantly (perhaps at least an order of magnitude) less if there were only passenger cars on the road.

It also needs to be removed for bicycles and pedestrians, who don't pay special taxes for that.

But bicycles don’t cause air pollution nor do they damage the roads. So you got me puzzled why they should be taxes. Pedestrians are taxed too much anyway

I was making an argument against taxing EVs. Or I tried to.

In the USA, snow removal is (mostly) not paid from gas tax.

Growth should pay for growth, so, no, we also don't need to pay for new roads.

Roads are also funded by property tax.