TCP Congestion

Via Slashdot: Fixing the unfairness of TCP congestion control
A nice article on the logic behind traffic management on the internet. If only we transportation engineers could simply drop packets (analogous to a helicopter vaporizing cars that were in queue?) The problem of course is that bandwidth use is not charged at marginal cost when it is in the congesting region, leading to overconsumption. The issue is the transaction costs associated with implementing a charging regime.

Speed limits for mode shifts

From the Telegraph:
15mph speed limit to force people out of cars

The UK is planning a series of 15 new “eco-towns”. As part of their design, a 15mph (Britain is not consistently metric) speed limit in the heart of these new towns hopes to discourage auto use, in stark contrast to the older new towns (Stevanage to Milton Keynes) which made freeflowing traffic a centerpiece.

Lane Reversal: Diverging Diamond Interchange

I heard this a few years ago, and going through old notes, decided to post, from the CBC series: As It Happens
To listen: Real Audio file, go to minute 21m:20s
The introductory text: “For as long as most of us can remember, the citizens of North America have been firmly entrenched on the right. Now, a bold and shocking proposal in the state of Ohio may result in a wild shift to the left. And it will come as no surprise that the French are involved.
The Ohio Department of Transportation is currently mulling over an unprecedented traffic diversion. If a recent recommendation comes to fruition, drivers on U.S. Highway 224 may find themselves driving — if only briefly — on the left side of the road. The lane-reversal plan is a proposed import from the city of Versailles, France, where Gallic drivers have found it to be “la rue juste”.”
This is a clever idea to avoid left-turn conflicts (or at least put them where you want them and make the crossovers seem like through movements. Wikipedia has an article.
My former classmate, Joe Bared, now at FHWA did a study with colleagues:
TechBrief: Drivers’ Evaluation of the Diverging Diamond Interchange, FHWA-HRT-07-048
The Hwy 224 proposal in Ohio was rejected. The proposal for Kansas City seems alive.

Congestion Pricing in NYC

From Streetsblog, Paterson Backs Pricing, Introduces Bill in Albany
Congestion Pricing in NYC may yet live. The politics are that the excess revenue from pricing goes to support transit. Locals support (generally), while auto commuters and others who drive into Manhattan oppose. I still have issues with an area scheme vs. a cordon scheme (the latter should have lower collection costs), but again this is a perfect vs. good situation.
My class did a case study on this last semester here

Wilde Lake Village Green RIP

Three links about the reconstruction of Wilde Lake Village Center (nee Wilde Lake Village Green in Columbia).
Wilde Lake was the first village in the planned community of Columbia, Maryland, and the Village Green was among the first buildings. And after 40 years, there are plans afoot to gut the center and rebuild it. While the verbal descriptions are not too helpful, it sounds like the standard banal new urbanist insta-downtown writ small (see e.g. Excelsior and Grand in St. Louis Park Minnesota or Rockville Town Square in Maryland) sans grocery store. I have an interest because it was the shopping center of my youth as well as my interest in planning and the history of Columbia. Times change I suppose, and if the market isn’t there for what exists, it must be changed, though maybe the Historic Preservationists have something to say.
Big plans for Wilde Lake: Owner seeks to raze, rebuild village center – Columbia Flier
Reinventing Wilde Lake the aim —
Reinventing Wilde Lake Village Green – Tales Of Two Cities
For my take on what’s become of Columbia, see: Levinson, David (2003) The Next America Revisited. Journal of Planning Education and Research Summer 2003, Volume 22, Number 4, pp. 329-345.

a blog about Networks and Places


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