You have to think about what a lot of the tax gets used for though...
For example, the USA may have cheaper fuels, but they don't have free healthcare like we do with the NHS.
Fuel tax is used to fund the NHS? I didn't know that.
The government seems pretty inefficient at spending tax money here tbh, there's allot of waste, and a certain amount of corruption too. But I think some of the reason is that they want people to drive less, there are a allot of cars here for such a small country.