Insurance included in gas prices

Imagine you go to the pump, and either a) the gas company gives you the option when you pump or b) when you pay they say "Would you like insurance with that?" for a few extra cents per gallon (or liter, whatever). Now, for each gallon you get insurance coverage for a specific amount of time (or miles) from the purchase time/mileage.. If you built a "credit card" for the insurance company and standardized the communication protocol, then you could have the charges payable to your favorite company. This would also allow for a VISA-like infrastructure, and states might even mandate it as a simpler way to make sure everyone was insured. With such a simple mechanism, I would bet many states would just make it manditory, and just swipe your insurance card to apply to the correct policy (or use a pin number or something)