I was informed, as 2011 waned, that my tax credit for commuting would fall from $230 a month to $125. This bothered me. Not because I feel I deserve a credit to commute, but because I can't figure out what the government is trying to do.

The fact is, if public transport is a 'good' we should all take advantage of no matter what, then the government should pay for it by taxing everyone and making it available for 'free' - as they do in Portland. Of course, I oppose this idea entirely. However, if the theory is that we can get people to do something that is 'good for everybody', then isn't this the way to do it? Half-measures, like credits, subsidies, and other methods of this ilk only mask what is possibly (though probably not) a problem - that public transportation isn't really viable. There are ways to determine whether this is true, but not for the average commuter.
What is the premise behind having a tax credit for public commutation? I like it, I'll use it if it's offered, but I didn't demand it, nor did I write Congress to keep it at $230/month. The cost, to me, of increased taxation due to the lower credit will be about $270 over the course of the year, so it's not a big deal. Why not just get rid of it altogether? If public transport is truly efficient, then it would make much more sense for me to take it, rather than driving into the city myself (or carpooling).
My commute is about $330/month. The cost of driving (assuming the Federal allowance of .55/mile and $150 a month parking) is about $780/month. Even if I made a more realistic assumption of about .25/mile, public transport is still an advantage. But public transport is heavily subsidized. So I really don't know which is more efficient, and determining this is very hard.
Here is the issue: Subsidies and tax breaks are supposed to promote the 'public good'. But how do I know which is more efficient, let alone even better, for me personally? If it is a 'public good', then its value will be transparent without subsidies and credits. I'll take whatever credits get offered. It would be crazy for me not to. But I'd much rather have a clear means of determining which makes more sense by comparing simple features like cost, time and effort (hey - in the end, I like reading on the train, so if it did cost more I'd probably still take it).
It is precisely this lack of transparency that makes other government initiatives, like Obamacare, a pure misallocation of resources. Unable to determine where our real efficiencies lie, we opt for what we assume is 'best' or costs us least. But we cannot know for sure if these things really make sense at all.