In some American cities, new or proposed transit lines are either core connectors, i.e. city-center circulator streetcars built for development purposes, or far-flung commuter rail extensions with few urban stops. Both are present in Providence, with the South County extension of the MBTA and the Core Connector, but worse circulators than in Providence are proposed elsewhere (for example, in New Haven), and exurb-focused commuter rail with parking lot stations is the standard in most Sunbelt cities and also in Massachusetts. At first I thought my opposition to both was just a matter of wonky support of a specific stop distance and service pattern that falls in between those two extremes, but recently, after attending Providence urbanist blogger meetings and also rereading old threads about New Haven, I realized there’s a political and social dimension to all this.

Recall that old American cities have a donut-shaped income distribution: gentrified in the center, poor in most other urban neighborhoods and inner suburbs, and middle-class to rich in most suburbs. Those two forms of bad transit are specifically built to cater to the rich parts of the metro area, and ignore the poor parts. The problem, of course, is that the poor parts are precisely where transit ridership is concentrated. People in the gentrified cores of smaller cities can walk; people in the suburbs own cars, and those cities have too many roads and too much parking for buses to be an even semi-reasonable alternative.

In Providence, as I recently brought up, the busiest buses follow Broad and North Main, and serve working-class and poor populations. The same is true in New Haven: the busiest line by far runs on Dixwell, connecting the Yale student ghetto, the in-between poor neighborhoods, and the strip malls in middle-class Hamden. So what service addition does a study by the South Central Regional Council of Governments (SCORAG) propose? Naturally, a circulator connecting Union Station with the New Haven Green. You could chalk this up to a belief in systemwide upgrades over building a few high-performance lines, but many outlying bus stops have no shelter, and the study says nothing about that.

When Peter Brassard first pitched the idea of a local rail shuttle service in Providence and its inner suburbs to us privately, the observation one of us made (I think it was Jef Nickerson, but I’m not sure) is that it would invert the usual relationship between infrastructure investment and income. This is mostly accidental – the mainline serves Olneyville and Pawtucket but not the East Side. But something like this is more likely than not when the focus is on serving reasonably dense neighborhoods and perhaps inner-suburban malls outside walking range.

The same is true of what I believe to be the most promising rail shuttle service in New Haven – namely, a service using the Farmington Canal Trail, which runs about 200 meters east of Dixwell, and could be reused by light rail reaching downtown New Haven on city streets or rapid transit connecting to the mainline with a very short tunnel or trench. With a stop spacing of a little less than a kilometer, modern rolling stock could average 35-40 km/h in service, double the speed of the current bus.

I suspect part of the bias against such service comes from the belief that building ten kilometers of light rail is expensive. Because there’s an implicit hierarchy in planners’ mind between services, they think a downgrade is an automatic cost saver, even when it’s not – for instance, when a bus on an abandoned railroad costs far more than most rail reactivation projects do. One of these mantras is that commuter rail infill is less expensive (and then they build infill stations at $100 million apiece, strategically located away from the intersection with the main bus corridor). As a rule of thumb, each of these downgrades just raises unit costs because of various overbuilding schemes until total cost is the same as if they’d built regular urban rail, but the benefits are much lower.

But it’s more than a technical bias; it’s also political bias. The Core Connector is explicitly a development project. It may even be a successful one, if it convinces local power broker Colin Kane to drop plans for building 7,000 parking spaces in the Jewelry District, as described in a recent paywalled article in Next American City. Development projects like this never go to extant low-income neighborhoods, unless there’s an explicit effort at gentrification, and usually locals protest against the displacement; neglect is much easier and less controversial than redevelopment.

The technical and political biases merge in one of the less challenged cost-effectiveness metrics, the cost per new rider. Although it’s presented in neutral terms – the cost is compared to the predicted total transit ridership if the project is built minus the predicted total if it is not – the results privilege adding choice riders (that is, those who already own a car and drive to work) over retaining existing riders. Although transit revivals happen, most of the world’s transit cities built out their systems before most people got cars, and people simply kept using transit instead of buying cars even as they moved into the middle class. Portland may have about the same metro area transit mode share as before it built light rail, but other cities of similar age lost ground and have even lower transit use.

It’s tricks like ignoring retention that lead Boston to downrate replacing the southern half of the Silver Line with light rail on its list of possible projects even though it would be very cheap by US standards per rider, and rate new commuter rail branches well beyond the continuous built-up area as more cost-effective. The rail bias factor implied by the computation for new riders is less than 0.5%: 130 new riders against 34,000 existing ones. A Transportation Research Board analysis finds the rail bias is in the 34-43% range. I suspect that if the Silver Line served richer areas than Roxbury, Boston would use a more reasonable rail bias than 130/34,000, bringing down costs per new rider by two orders of magnitude. New York went ahead with Second Avenue Subway; it is undoubtedly the most important subway project in the region, but the next best corridors, e.g. Utica, serving less chic neighborhoods than the Upper East Side, are ignored.

The technical reason to build urban rail a certain way – own-right-of-way, stops roughly every kilometer within the city, etc. – is of course separate. Technical characteristics do not tell you which neighborhoods to serve, not without first looking into existing demand patterns. It is just fortunate that New Haven has a right-of-way closely paralleling Dixwell, and unfortunate that Providence has none paralleling Broad. But the income donuts, and more generally the connection between density and old industrial development that is usually working-class (since gentrification in such cities is within walking distance of the core rather than within transit distance), have certain social implications. The most annoying to the planner and the government official is that they must invest in poor neighborhoods as they are, and do not have a special reason to try to foist change upon them.

Or they can just build core connectors for the cities and park-and-ride extensions for the suburbs. The FTA will fund these no matter what; its cost-effectiveness metrics are biased that way to avoid having to send every penny it has available to a few expensive but high-ridership lines such as Second Avenue Subway. The developers will like them, because of real or imagined property value benefits. The state will like them – state governments are dominated by suburbanites and urban developers and view transit as pork rather than as useful spending based on ridership metrics; Rhode Island is much likelier to find support for development in the Jewelry District than for boring rail lines in already-developed Providence neighborhoods. It’s a win-win for everyone except the riders, and they don’t count.