[Developer_Tom]

Yes, fuel duty does bring in a lot of money, but it doesn’t go directly into fixing the roads—it generally goes into the government’s general budget.

Local councils who are responsible for fixing the roads have been underfunded for years and is normally the area that gets squeezed the most. The British weather doesn’t help too with constant rain and freezing winters…

[vasco]

No specific tax in any country funds things directly. It's just a ploy to get people to accept new taxes. Every tax is whatever % it is of the global tax revenue and that's it, and if you know what a tax dollar is used for you can look at the overall budget of expenses.

For example, if I say I will create a tax to protect the children, exclusively used to fund orphanages, you go oh man that sounds great. But you already have a huge budget and you already have existing taxes you could've raised for that. So the only reason you do it like this is optics and so that later you can repurpose the tax. Reading a bit about historical reasons for some taxes is a good way to learn this.

Specific taxes like this can and do modulate demand and can adjust the costs to the actual users, but very rarely for funding isn't it only a sleight of hand.

[hgomersall]

Taxes don't pay for things at all in a monetarily sovereign country. The spending happens from new money creation. The tax (among other things) is about resource liberation to prevent inflationary pressure.