Schoolhouse rock for transportation funding

What we need is a schoolhouse rock for transportation funding.
The public does not know where the money for roads comes from or goes to. It does not understand trust funds. It has no clue the magnitude of the gas tax or other transportation funding sources.
I could say the same about policy-makers.
Transportation funding is becoming a shell-game promulgated by Washington because of fear that elected officials have of being unelected by the mathematically illiterate.
It has to be cheaper to teach people math than to suffer through inadequate transportation funding out of general revenue because a general sales tax seems cheaper (at e.g. 1/2 percent) than a gas tax (at e.g. 20 cents / gallon) since 1/2 < 20.