I was skeptical of this being true since fuel duty is notoriously high in the UK, so I did a quick fact check.
Based on the change in 1937 you are "technically" correct, in that none of the motoring taxes are ring fenced for road funds since 1937.
However the opposite is true of what you are implying... income from fuel duty alone is generally around 3 times larger than all road maintenance spending (a fairly steady +25bn/yr [0] Vs -8bn/yr [1] over the last decade).
In other words, although it's officially one big tax pot, motoring taxes pay for road network expenditure more than 3 times over.
This is why they are introducing the per mile EV tax, because fuel duty provided a proportional tax to road use, but EVs skip that and electricity can't be so easily taxed for road use specifically.
TLDR, UK road users pay for far more than the road network.
[0] https://www.statista.com/statistics/284323/united-kingdom-hm...
[1] https://www.statista.com/statistics/533171/annual-road-trans...
Right, but driving has far more externalities than just the cost of the roads. For example:
> Results suggest that each kilometer driven by car incurs an external cost of €0.11, while cycling and walking represent benefits of €0.18 and €0.37 per kilometer. Extrapolated to the total number of passenger kilometers driven, cycled or walked in the European Union, the cost of automobility is about €500 billion per year. Due to positive health effects, cycling is an external benefit worth €24 billion per year and walking €66 billion per year.
From "The Social Cost of Automobility, Cycling and Walking in the European Union", https://www.sciencedirect.com/science/article/abs/pii/S09218... (which I heard about from a CityNerd video https://www.youtube.com/watch?v=qp75-46PnMY )
This is interesting, how is this accomplished?
Over here there was some proposal some years ago to move to a per-mile taxation, with higher tax in congested areas. All managed by some kind of GPS device in each car. There was much opposition as people didn't want the government spying on them via this GPS device, so the plan was eventually dropped.
A simpler approach would be to just record the mileage during annual inspections, but hey why make it simple when you can have some public-private grift making zillions on selling these GPS devices and running the infrastructure for them..