Thoughtful commenter MLD writes about my recent comments on the Brookings study:

In Modesto the average block group resident can get to 38% of metro area jobs in 90 minutes on transit. What about the other 62%? Are they accessible from somewhere on transit? Or are they not accessible by transit at all? That’s a really important distinction when you are trying to compare different sized cities and it distorts the data when they limit themselves to the 90 minute radius.

As I suggested in the comments, I thought that 90 minutes was too generous–MLD suggests here, though I am not sure–that 90 minutes is too restrictive. When I said 90 minutes was too generous to the Brookings folks, they countered that it really wasn’t, given average transit commute times (versus average commute times by any mode, which is what I think they should use.)

It brings up a salient question: how long does a transit trip have to be before it is the same as having no accessibility whatsoever? I’m a high value of time person, so that idea of a 90-minute commute is troublesome. But that’s not true for everybody. As Stephen Wright pointed out: Any place is walkable if you’ve got the time.

I’m sympathetic to the arguments, for example, that HSR is needed in the Central Valley because people there have no accessibility to either LA or SF except by car. However, that’s not strictly true. They have Greyhound and Amtrack, which I just tried out a few weeks ago, and…they’re terrible. (I originally used a different phrase, but this here’s a family blog.) How terrible must they be before basic fairness in public policy kicks in and we provide them connectivity to economic engines of the regions?

Ed Glaeser, I think, would say: if they want access, they should move. There’s something to that logic, too. It’s what I did. I didn’t expect the world to spend billions to come to me.

The second salient question: what percentage of urban population should have access to a job via transit?

You could make argument #1: 100 percent. Transit should be just like any other municipal service, like garbage collection. If you live in a city, and that city has transit, you should have it.

Ok. That makes my head spin with the expense associated with it, but I’ve argued that I hate the transit-subsidy v. car-subsidy babble because it’s an argument that transit people are always going to lose outside their choir–and relative subsidies aren’t the point anyway.

The point is: transit is high-capital, low-revenue/high social returns endeavor which needs a subsidy to operate, so why can’t collectives opt to pool their resources and provide the service to themselves even if the service requires a subsidy? Nobody expects other basic urban services to pay for themselves, like street cleaning. Why can’t transit just be like that? Nobody expects national defense to pay its own way.

Argument #2: 100 percent is cost-prohibitive and unnecessary, so the percentage should be lower.

Not everybody in the city wants a job. We have retired people, bike and walk commuters, etc. According to the BLS, about 60 percent of Americans are legally employed. So would 60 percent be right?

Would some lower value than 60 percent be right?

Should I worry that 62 percent of Modesto residents can’t get to a job by transit, if they, themselves don’t worry about it?

Just as with the Central Valley example, it’s possible to say that if you choose to live in a area without transit access, then it must not be important to you, so why should the rest of us spend the $$$ to make it happen for you? But then there’s the affordability problem: not everybody can live precisely where they want with the amenity set they want, due to budget constraints.

Even so, transit is useful for a lot of travel unrelated to job access. Perhaps 100 percent would want it, regardless of their job status.

I have argued myself into a corner.