- 2,767
From wikipedia:FamineHow much is garnered in fuel duty/tax? How much is spent on maintaining/upgrading the roads?
I can tell you that just about £1.2 billion was spent on the UK's road network last year. We pay 70p tax per litre, so the money spent on the road equates to the tax from 369 million gallons of petrol sold.
Now the average car in the UK returns about 38mpg, and travels 10,000 miles a year - so it uses 263 gallons of petrol a year. There's 30 million cars in the UK, so that's 7.9 BILLION gallons of petrol used per year.
Less than 5% of revenue garnered from tax on petrol went towards the road network.
Investigate it for your country. I doubt it'll be as bad as that, but it won't be anywhere near even a quarter.
Now on the subjec of expenditures on our roads, a quick search revealed this:The tax on fuel in Canada can vary greatly between provinces. On average, 40 to 50% of the total price of gas at the pump is tax. The federal government receives its share through the excise tax (10 ¢/L) and the Goods and Services Tax (7% of the whole price, taxes included - it is a tax on a tax). Most of the variation comes from the provincial tax. The lowest being the Yukon with 6.2 cents per litre and the highest being Newfoundland and Labrador with 16.5 cents per litre. In addition to this there is sometime provincial sales tax, such as in Quebec (a tax on a tax on a tax), and in larger urban centers there is a transit tax. Taxes collected by the federal government (totaling $10,000,000,000 a year) do not get reserved for any specific program. However, provincial taxes usually go to fund road repair and construction.

Granted, that include railways and air traffic, but as you can see, it's quite marginal. Bear in mind that these numbers are from almost 10 years ago... I think it's pretty safe to say that while the money isn't reserved to be spent on our road system, it does barely cover for it, if at all.
We pay more for our gas than in the US, and most likely spend much less than they do on our roads (there isn't much going on up North), so I'd say that the same applies for them. In the end, I wouldn't mind the recent surge in gas prices at all if it was spent to improve on the quality of our roads, which are for the most part in horrible conditions. A few hours ago I had to stop once again to closely inspect two wheels, as was expecting a bent rim after going through an humongous pothole.