One of the best ways to promote clean transportation is to discourage dirty transportation. But despite decades of Presidents saying they will reduce our dependence on fossil fuels (quoteshere; video here), nothing of the sort has happened and one of the biggest culprits of pollution, the automobile, has probably gotten more help than anything else.
People may complain about the price of gas going up because the raw number is going up, but — adjusted for inflation — gasoline taxes are at their lowest in decades.