GeorgeBush.com put together this calculator to illustrate how much one will pay because of John Kelly's proposal of 50 cents/gallon gas tax increase. According to the calculator, I would pay $337.96 more under Kelly's administration.
If you don't regularly track your daily expenses like gas, this calculator may serve the purpose to get you a quick estimate of your annual gas cost. Note it is kind of tricky that the calculator asks for your weekly driving distance. I originally put an estimate of my annual mileage and the result scared me to death :-)
By all means, any gas tax favors the riches, because it is not easy to cut much auto usage. Kelly's proposal seems to be contradictory to his aim to reshuffle the income tax system by unwinding the Bush tax cut for people earning more than $200,000 per year.