Not sure whether I understand everything you wrote. I am not a businessman, but can't miles be deducted by every business, not only the small ones (and has nothing to do with level playing field)? And isn't it eplicit tax law that you CAN'T deduct cost other than cars/trucks?

Do we expect consumers to bear the full cost per mile, as you ask? Well, you can make the point that transportation should be subsidized in order to stimulate the economy ... but shouldn't the endprice reflect the actual cost of different modes of transportation? OK, in the 60s, where oil was cheap and seemingly unlimited, it made sense to favor the car given all the economic activity related to it (construction, auto industry, gas stations, insurance companies etc.). But nowadays, given the economic, ecologic and political cost of oil, doesn't it make sense to go towards less energy intensive mass transit?