If you make a tax-deductible donation to your local transit authority (check your state if it's deductible) then the government is basically paying more for mass transportation than they had budgeted. Our taxes are one of our most powerful tools in the US for deciding what gets funded and nobody uses that tool. Likely because it's hard enough to stay fed than donate sums of cash to already-functioning institutions, but imagine if enough people just did this a little.