Last week, TOW linked to this interesting study from the Federal Transit Administration. It computes and compares emissions and energy use per passenger mile across different transportation modes. Transit does very well against personal automobiles (as you’d expect, but as is often denied by the Wendell Cox-es of the world). So too does transit perform well on measures of life-cycle emissions per passenger mile, which includes the carbon content of construction and maintenance as well as daily operation. The results definitely suggest that, other things equal, building and using more transit is a good idea, from an environmental and climate change standpoint.
But a couple of interesting things stand out. One is that increasing transit ridership has a dramatic effect on average emissions, especially for buses. The reason, of course, is that a lot of carbon is emitted setting up and running a train or a bus, but very little additional carbon is emitted as riders are added. The get the most emission savings out of the technology, then, you want to run transit pretty full. And the other thing that stands out is that, according to research cited by the FTA, the effect that transit has on land-use produces twice the reduction in emissions as the mode shift itself.
What this means is that if you’re interested in reducing the nation’s carbon emissions, you ought to be interested in building new transit. But what it also suggests is that just laying the tracks or buying the buses, and doing nothing else insitutionally, is leaving most of the potential carbon savings from transit on the table. You also need to work to maximize ridership, by eliminating silly automobile subsidies, for instance (like free parking and underpriced roads), or by making your system easier to use (by partnering with Google Transit). And you need to allow transit to shape development around stations, by changing zoning rules and street patterns (as Tysons Corner intends to do), and by facilitating density in other ways (like ensuring that NIMBYism doesn’t stand in the way of quality, dense, developments).
These policy changes seem like they should be easy — they will often increase property values and tax revenues — but change in the face of existing interests is difficult, and many people simply don’t get it. But we’re only hurting ourselves if we spend billions on these wonderful new transportation technologies, only to ignore the little institutional changes that will maximize the investments.