Slippery slope. Assuming, for the moment that it is a good idea to fund the highway system primarily or exclusively with taxes that approximate user fees, that

Slippery slope. Assuming, for the moment that it is a good idea to fund the highway system primarily or exclusively with taxes that approximate user fees, that does not imply that it necessarily makes sense to pay for education the same way. Nearly everyone who derives benefit from the highway system, directly or indirectly helps pay the tax, directly or indirectly. Higher fuel taxes would translate directly to higher prices for goods and services that use the highway system. Other things supported by taxation may be different - education, for example. There's reason to believe that having a well educated population is good for everyone who lives in the society, even people who are not, at that time receiving education. User fees are contrary to the goal of educating as many people to a certain level as possible, so a different model probably works better. it makes supporting the less popular elements of government spending harder Well, in a government that's more or less democratic, implementing less popular policies should be harder than implementing popular ones. That's kind of the point.