March 2, 2011

Not (nearly) big enough for nodes

When I first started going to meetings about the Tompkins County Comprehensive Plan, the idea of building on existing transportation nodes seemed sensible and appealing, at least when compared to scattering houses across the landscape.

As I've learned more about planning, however, I've come to the somewhat awkward conclusion that "nodal development" as suggested for Tompkins County and Dryden is not so great an idea. The theory didn't seem to fit the reality, but I couldn't really put my finger on why.

The Route 13/366 Corridor Study (which I mostly thought was awful) talks about Nodal Development in the abstract, without ever really pinning it down. Tracking down the study that followed that one, the Route 96 Corridor Study, though, brought me to some more concrete definitions:

A node, as used in the Tompkins County Comprehensive Plan, refers to a relatively dense concentration of mixed-use development. Nodes include, and the concept is derived from, the traditional villages in the county as well as areas with infrastructure and an existing base of housing, services and/or employment that may function as a node or support development of a node in the future. It is intended that nodes provide employment, a mix of types of residences, and commercial and community services in a walkable community that can be connected to larger employment and service centers by public transit.

In order to keep a node walkable it should encompass roughly a 1/2-mile radius from the commercial core to the edge, with the densest residential development within 1/4 mile of a transit stop. (Ideally there should be a distinct rural/urban edge to the node.) This means a total land area of approximately 500 acres. Studies have indicated that a population of about 2,000 to 2,500 is required to support the most basic neighborhood-scale commercial services.

If half of the gross acreage, taking out land for streets, parks, public and commercial buildings, etc., is devoted to residential development and the average household size is estimated to be 2.5 persons, that requires a density of at least four to five units per acre. Of course greater densities will make it possible to provide a greater range of services (and make these services more economically viable) thus reducing further the need for vehicular trips. A well-planned node could easily accommodate a population in excess of 6,000 and still maintain the walkability standards. (Page 2, Final Report, February 4, 2010)

Here, finally, we have a cluster of key concepts that go beyond "dense mixed-use". "Walkable" is essential for the traffic-reduction and environmental benefits of nodes to actually work. There are populations given here - 2000 to 2500 as a minimum is lower than the 3500 to 4000 I've heard elsewhere, but at least those are actually numbers. 500 acres also provides a rough guideline, and it's worth noting that the acreage centers on a point. Spreading 500 acres along a highway doesn't create walkability, after all.

There's one major problem with this definition, however, which may be part of why it doesn't appear in the Route 13/366 Corridor Study: by this definition there are no nodes in Dryden, and only one place - the Village of Dryden - that is even close. In 2000, it had 1832 residents, though spread across around 1000 acres. "Greater Varna" had 976 residents. "Downtown" Varna had a mere 679 residents, Freeville 505, and Etna 379.

A 2010 study, Creating Walkable Neighborhood Districts (1.4MB PDF), includes estimates of how many square feet of different types of retail an average household can sustain. There's 72 square feet per household total, with about 40 of that possibly in a neighborhood-level center - but only 15 likely in an age with concentrated retail centers. That means 1000 households will support a 15,000 square foot "corner grocery" (though that seems big for a corner grocery), 2000 a 30,000 square foot small neighborhood business district, and 3300 a 50,000 square foot larger business district.

These estimates appear to hold true even for the places in the Town of Dryden that look (to planners) most like possible nodes.

The Village of Dryden certainly has stores, restaurants, and places to work, but it's not particularly organized as a node. Clark's Food Mart does well by serving a large area (including Freeville) between Ithaca and Cortland, not just by serving the people who walk to it. I took the 2006 exodus from the center of the Village to North Street as a sign that (visible) parking was more important than a central location to a lot of businesses, though from what I can tell there was more going on than that.

Varna used to have more business than it has today, including a drugstore that advertised itself as "deep in the heart of downtown Varna". There was a grocery store and a liquor store, but these were all fading by the 1960s. Stores drawing business from the road stayed closer to the newly moved Route 13, while stores serving local residents concentrated at East Hill Plaza in the Town of Ithaca, 2.5 miles away.

There are three main factors at work limiting the effectiveness of nodal development as a model for densifying these areas:

  • Completeness (stores, schools, work, entertainment, etc.)

  • Distance from other areas that support enrichment or consumption

  • The relatively low cost of travel

Completeness is hard. Once people get into a car for one thing, they're likely to add other things to the trip. If you have to go to work in Ithaca, you're likely to buy groceries on the way home. School is slightly different because of its dedicated bus system, but again, kids going to school far from home connects them with a social circle you're likely to drive to sometime - and probably shop or find other entertainment on the way. (Bus systems generally may reduce the tendency of people to stop their trips in the middle.) The Village of Dryden has a much more complete set of stores, schools, and jobs than any place else in Dryden, but even there it's clear that many people regularly drive to Ithaca or Cortland or beyond.

The Village of Dryden's location helps it, though, to maintain that completeness. As George Goodrich put it in 1897, "the proximity of Varna to Ithaca has always interfered with its prosperity as a business center." Even if Varna doubled in population overnight (adding another 385 housing units), East Hill Plaza wouldn't get any further away, most of its residents would likely be commuting elsewhere, and its children would go to school in Caroline. It seems that Varna hasn't been close to "complete" since its school shut down, and even in what seem to have been its peak as a cohesive place it has always been tied to Ithaca and the state highway.

The last factor, the cost of travel, explains how it was possible for Varna, Etna, Freeville, and Dryden all to be relatively "complete" places before the advent of the automobile - despite having populations far below 2000. They were all connected by the railroad, certainly, and you could walk or ride from place to place - but getting from Varna to East Hill Plaza wasn't the simple matter it is in a car with well-paved roads. The cost of travel was what created the "natural" node system of cities, villages, hamlets, and countryside that dominated before the car. It could return with higher gasoline prices, but habits will take a while to change unless prices are dramatically higher.

Unfortunately, much of the discussion around zoning in development has taken a line that "you can have the stores and walkability you want if only you'll let in denser development." The reality is much more complicated - the level of density needed is far greater than that usually suggested, and the benefits for each added unit of density will stay small for a very long time.

Overall, my conclusion is that rapidly densifying the Town of Dryden, even small areas in the Town of Dryden, is pretty much a terrible idea. The Village of Dryden is the only place that could plausibly become a complete walkable neighborhood, and even there it would be a stretch because so much of the population works elsewhere. There are real costs to increased density, and the benefits of density require a critical mass that we're not likely to achieve here. At best we're likely destined to become a gray area if we take that path.

If the County is serious about increasing density, they'd be much wiser to put that density in places where its benefits are easily realized. I hate to say that a lot of this development doesn't likely belong in Dryden, but looking at the Downtown Ithaca Alliance's Downtown 2020 Strategic Plan makes a lot more sense to me than any vision I've seen for large scale development in the Town of Dryden. 1500 units in places where they fit a lot more naturally? Sounds sane.

Meanwhile, Dryden should work on the kinds of things Dryden is good at. Strengthen our villages and hamlets, yes, and do what we can to reinforce our neighborhoods and farms. We don't need to destroy these places to improve them.

Posted by simon at March 2, 2011 5:12 PM in ,
Note on photos


Jason C said:

Great thoughts and opinions! Thanks for writing it up.
I hearby give you the title of "Nodal Development Expert" based on the fact that if you google Nodal Development 2 of the top 3 results (out of 1,960,000 results) are Living In Dryden posts. And expect that once indexed this post should be #1.