Last Thursday, Council adopted a resolution directing the City manager to gate a future extension of Aldwyche Drive. Aldwyche Drive is a short street in the Barton Oaks neighborhood in South Austin. It dead-ends at a vacant tract, just a few hundred feet shy of Lightsey Road in the South Lamar neighborhood. PSW Real Estate is developing that vacant tract and will, in compliance with the City's subdivision regulations, construct and dedicate a public street connecting Aldwyche to Lightsey.
The general location (if not the precise alignment) of the Aldwyche extension is shown in blue below.
Thanks to the Council resolution, the Aldwyche extension will have a "crash gate" blocking cars from entering Aldwyche from Lightsey, and vice versa, although it will not block pedestrians or bicyclists.
The gate is a mistake, in my opinion. I understand why Council voted for it. This development has been particularly contentious. The Council members who voted "yes" were probably trying to give the Barton Oaks homeowners some peace of mind while letting the developer get on down the road (so to speak) with its project. Some Council members even may have calculated that, without a resolution, the acrimony might cause the developer to back out of the project, in which case there would be no extension of Aldwyche anyway.
But one point that has not been emphasized enough is just how badly disconnected the neighborhood is. I live in the neighborhood and can attest to its disconnectedness. For example, the neighborhood doesn't have a single through street. The closest thing is actually three roads -- Clawson, Lightsey and Del Curto -- which trace out a herky-jerky path from the Ben White frontage road to South Lamar Boulevard. Because there is no true intersection along its 1.5 length, it effectively cleaves the neighborhood in two. The red line shown below is impassable except at either end.
(For simplicity's sake, I've included the small Barton Oaks neighborhood within the boundary of the South Lamar neighborhood, shown in blue.)
Another way to illustrate the lack of connectivity is to sketch the streets that are reachable along the street network within a given distance of a specific location. For example, the map below shows all the streets that are reachable within one-half mile of West Mary and 3rd Street, as measured along the street network.* (The blue circle has a half-mile radius as the crow flies.)
This is sort of a "dye test" for connectivity. A green-filled circle, like this one, is a sign the area is highly connected. There are many potential destinations within a short distance, and many alternative routes to get to them.
Performing the same dye test on the "Dead Man's curve" that connects Lightsey and Del Curto -- near the terminus of the Aldwyche extension, shown in red -- shows an absurdly disconnected street network. (If this were human tissue, we would call it "necrotic.")
Ditto for Aldwyche's dead end.
Aldwyche and the Dead Man's curve on Lightsey -- although just a few hundred feet apart -- are not within one-half mile of each other as measured along the street network. (They are not even within a mile of each other.) But, more importantly. very few places are within a half mile of either location. A disconnected street network not only provides few routes from one location to another, it provides few nearby locations, period. The Aldwyche extension would essentially double the number of locations within one-half mile of either Lightsey or Aldwyche.
This lack of connectivity imposes very real costs on both neighborhood residents and nonresidents:
1. it forces neighborhood residents to make long, circuitous trips to run even simple errands;
2. it forces residents onto congested arterials like South Lamar even for short trips, exacerbating the congestion experienced by everyone, residents and non-residents alike; and
3. the impermeability of the network limits the routes available to non-residents.
Of course, some people will cite #3 as a benefit of disconnectivity ("Cut-through traffic is bad!!"), but it should be counted as a cost simply as a matter of fairness. The streets in the South Lamar neighborhood ought to provide some benefit to people living in Zilker or Bouldin Creek or south of Ben White, just like their streets provide some benefit to me.
The lesson here is that we cannot rely on the private subdivision process to improve the connectivity of our older neighborhoods. Subdivisions that actually propose new connectivity are rare. Too rare. And, because they are ad hoc, they generate a lot of angst among the handful of homeowners most directly affected. Ultimately, any solution will require leadership and planning by the city.
*I used this app to create these maps. Author unknown.