As far as the economics go, it's not a matter of pain for people with lower incomes versus no pain for people with lower incomes. It's some pain now, versus a huge a amount of pain later.
I strongly believe that the major reason people are against fuel taxes is because they are looking at their short term economic interests, instead of long term economic interests for their children and their children's children.
I would love it if my area had a bus service, but the closest bus stop is 15 miles away and even then the nearest bus stop to work is 3 miles away from my building. That is a LOT of walking...I would have to leave for work at 4:00am and wouldn't get home until after 10:00pm. Yeah, I'd be fit, but my life would suck! I do agree more public transportation here would be great, but I'm not holding my breath.
And, the reason people build houses in the country is because we want to be away from the crime, the pollution, the hectic city (heck, I only live outside a town, not a city, and I still hate going there!). Luckily we do have a little grocery store at the end of our road so we don't need to drive 15 miles into town for a gallon of milk.