Which commodities post their prices on very large signs on U.S. street corners?

Milk? Sugar? No. Only gasoline and diesel fuel. And in recent weeks, the price of these two commodities has risen as the price of crude oil has climbed.

To explain fuel prices, API has produced the primer above called, "What's Up with Gasoline Prices?" It's a quick read loaded with helpful graphs that illustrate the relationship between crude oil and gasoline prices as well as the impact of other factors, including global crude oil supplies and the value of the dollar.

Federal, state and local excise taxes also have a big impact on pump prices. Check out the latest information on excise taxes motorists pay at the pump.

Which state has the highest gasoline taxes? California, where motorists pay the 67 cents a gallon in taxes. Contrast that figure with Alaska, where motorists pay 26.4 cents a gallon in taxes. For more information, see the state-by-state tax lists for both gasoline and diesel fuel.