I saw in the San Diego newspaper an article that the CA Legislature is loosing road tax money due to the mpg of the efficiency of cars, e-cars and carpool vans. Their proposal is to tax the miles you drive. The data base will be gained by asking for 5000 "volunteers". I can see many problems on how the data will be collected. Maybe using the smog testing stations and/or the car's onboard computer. This should be interesting to see how this program will develop. Saw another reference of charging more for your car/truck registration. Wish the legislature would take the $68.4 BILLION "High Speed Train" and fix the roads and bridges. Makes more sense to me.