Leaving aside, for the moment, that the surrounding neighborhoods desperately and vociferously don't want to be tied together, here's my commentary:
Excellent posting, Dan.
I had understood that due to the economic climate, the Indian Spring Country CLub project was stalled. I guess I was in error, but I must also mention that the local media such as the Gazette haven't let out a peep, one way or another.
I attended one of the pubilc meetings some 4 years ago, held at the old Saddlebrook Elementary school which is now the HQ of the Park Police. The plans as laid out showed that Poplar Run Drive would effectively be a first-approximation to a "Northwest Branch Parkway", at least in the minds of the folks from Tivoli.
Now, first, there are some ambiguities in the dilemma between cul-de-sacs and grid-pattern.
In my humble opinion, if you laid out a grid-pattern development, as seen in the District from the moment L'Enfant touched pen to parchment, all will go the way the theorists like to say: no matter where you are, all streets being equal, you can get from any place to any other place however you want, and people will tend to spread out their routes according the amorphous average of their random trip origins and random trip destinations. If you make every 5th or 10th street a double-wide arterial and every 20th street freeway, you will get useful traffic flows, and even if the freeway is jammed you can take the side streets.
Yet even the best laid plans of grid-pattern designers can come up against the harsh realities of terrain.
You'd think that Houston TX -- almost entirely grid pattern, everything built since 1970 or so, for sure -- would be the textbook example of how packed freeways can spill over onto side streets in a diffusion.
But it didn't work that way, not even when I lived there back in the 1970s and the freeways were pretty new.
The terrain got in the way.
Houston -- at least in the non-downtown/non-port areas -- is dead level and all of the drainiage is by sunken ditches referred to as "bayous". On only about one street of 10 would that street actually bridge the bayou.
See a map at Sharpstown Village ("near west" Houston) and look towards the top portion, the area bounded by Bissonet, Beechnut, Fondren, Bellaire, and Hillcroft. Note that between Sandpiper and Bintliff runs a drainage ditch. And even with one in three of the (more or less) grid pattern streets bridged over the bayou, that neighborhood is effectively cut in half. There are only two routes that go directly through the entire neighborhood, one north-south and one east-west.
Effectively this is a prime example of "connected cul-de-sacs". Yet even with a far higher rate than we see here of bridging of what MNCPPC might call "very minor streams", even back in the late 1970s trying to get through that neighborhood as an alternative to rush-hour traffic on the arterial streets was something of a traffic nightmare. I know, I used to drive it a lot.
My point is this: connecting cul-de-sacs is in no way a panacea. It only approaches that when you have nearly 100-percent grid connectivity across the entire region, or you get chokepoints. Whether or not the cul-de-sacs are small, or are large portions of otherwise connected cities separated by terrain and chokepoints, the whole "distributed traffic flow" ideal falls apart. It's only a "perfect case" that fits that bill.
That being said, more and better minor-arterials become necessary. In our area, due to the terrain and all sorts of streams large-and-small that have aggressive preservation advocates, these are hard to arrange. You have to locate them running parallel to the stream flows in most cases, and Poplar Run Drive will be a prime example of that.
Just keep in mind that it's going to get a lot of cut-through traffic, which is what neighborhood people call "diffusion". They don't like it.
In my opinion, you can better approach the grid-pattern ideal by having a lot more bridging of small streams serving a lot more small streets.
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