This article leaves out the obvious reason that has long been the reason park and rides are added to projects I work on in the AA phase - goosing up ridership. Federal funding rating has long been based on cost per new rider, and if you can't get costs down, you can always get ridership up (in the models, at least) by adding park and rides.
FTA has now published new guidelines (PDF) that emphasize transit supportive land use at the same level as cost effectiveness (which is also no longer based on cost per new rider, as well) so hopefully we'll start to see a shift in the next few years as projects conceived and developed under these new guidelines move into engineering and construction.
This may be more important than the congestion-fighting mentality I've described in recent posts in accounting for the proliferation of park-and-ride lots and garages in transit systems new and old. Both ideas flow from, and reinforce, the Kotkinist idea that the ideal commute is a solo drive in a personal car from the driveway of a single-family home to a parking lot.
I've heard the complaints over the years about the cost-benefit requirements for various Federal transit capital funding programs. In principle I'm in favor of cost-benefit analysis. Who wouldn't want to know whether they're getting their money's worth?
The main complaint I heard was that there was a double standard: transit projects were being asked to justify their funding in ways that most road projects would have completely flopped. And yeah, it's hypocritical *and* idiotic to care about one set of costs but not another.
I had thought that that was the only real problem with these cost-benefit analyses, and it seemed like it had been fairly well covered by other bloggers. I assumed that the "benefit" part of the formula represented something that more or less corresponded to an actual benefit. Boy was I wrong.
The metric was referred to as the "cost per new rider," but that's a bit vague. The official term is "incremental cost per incremental rider." To estimate it, a transit planner comes up with ridership estimates for the entire system if the project is built and for a no-build scenario, and divides the difference by the amortized cost of the project.
Does this make sense to anyone but a bureaucrat? When would you ever do a return on investment analysis where the "return" was simply providing a service? If you're deciding whether to build a factory, would you base your decision on the cost per unit? No, you'd look at the cost per dollar of profit. If you're a sane government official deciding whether to build a soup kitchen, would you look at the cost of providing a meal? No, you'd look at the cost of keeping people from going hungry.
Similarly, if you're deciding whether to build a transit facility, why would you give a shit how many people use it? Your ultimate goal is not to get people to ride the thing. It's to reduce pollution, or carnage, or to increase efficiency, improve society or provide access. If your project can do all those things without anyone actually riding it, that's better!
In general, yes it's true that a commuter who's on a train isn't driving, and therefore not polluting, using gasoline or running people over. But that's where the park-and-rides come in. If a commuter is only on your train for half their commute, they're still behind the wheel for the other half, polluting, burning gas and putting lives in danger the whole way. And if they then stay in the car for errands on the way home, that's more driving, plus they're shopping at car-oriented stores.
What's worse is that a park-and-ride can induce more driving, because it can make a car-oriented suburban life affordable and convenient for people who work downtown but wouldn't pay to drive all the way downtown, either in pure dollar terms or in convenience cost. If a park-and-ride encourages someone to move from an apartment in a walkable neighborhood to a house in a car-dependent suburb, that may make Joel Kotkin happy, but it sucks for the environment.
That's what's missing from the Federal metric. What is the incremental cost per incremental rider in terms of transit trips still half driven? What is the cost in terms of induced driving for errands? In terms of induced driving by spouses and children? Nowhere.
So what about these new guidelines? Well, I'm not too impressed. They talk a lot about parking - presumably from the point of view that the more parking there is at transit stations the better, but it's actually ambiguous.
What I'd like to see is some attempt to quantify how much less driving people would do with the project in place than without it. Of course, you'd also have to take into account competing road projects that are being funded at the same time.