Wikipedia saith that, as of 2007, 93.5% of the Federal contribution to the Interstate Highway System was funded by gas and vehicle taxes.
http://en.wikipedia.org/wiki/Interstate_Highways#Financing
And it notes that 1/6th of gas taxes and other user fee-like financing mechanisms are diverted toward public transit.
My favorite example: the price of books in the US and Canada. Just grabbed a random recent hardcover off my shelves. It's labeled "USA $25.95 Canada $32.50". I believe that price differential got established back when the US dollar was worth $1.25 Canadian -- but it still exists, even though the two currencies are now roughly on par. It's the exact same product with what is effectively a 25% markup for Canadians for no good reason.
I thought that our 19 cents/gallon tax on gasoline is what is used for road repairs etc. Is this not the case?
And here: https://en.wikipedia.org/wiki/Fuel_taxes_in_the_United_State...
$25 billion received via gas taxes at the federal level in 2006 (60% spent on roads). $70 billion spent by feds in 2012.
http://www.subsidyscope.com/transportation/direct-expenditur...