Looking at the new controlled-choice student assignment model

Not on a high horse. Just don't like being accused of making an error in methodology, and then guessing (wrongly) at that methodology. And yes, assuming that only 1/3 of school aged children go to ES was a critical error.

The density that I reported (3141/square mile) is the density of the areas inhabited by people within the city limits of Cary, and is represenative of the density for the average resident. This figure was corroborated by at least a dozen different websites. I'm guessing that your calculated figure takes into account water, industrial areas, and other large, uninhabitable areas, and while it represents an average density for the entire city, it is not representative of densities experienced by most residents of Cary.

In several other blog posts on this forum, I showed that the average distance from any location in Wake County to an ES is 1.8 miles. Obviously that is not true for everyone, but it is accurate for the majority of ES kids in Wake County.

I took a look at Davis Dr and drew a 1.5 mile circle around it - and guess what - there are 4 other elementary schools within 1.5 miles of Davis Dr ES.

First I call BS. Using Google Maps Distance Calculator, there is only 1 school - Turner Creek ES at 1.443 miles -- that is within 1.5 miles of Davis Drive ES.

BUT... I did not say within 1.5 miles of Davis Drive ES - I said within 1 mile of the school. A 1 mile radius is only 3.14 square miles. as opposed to the 7.1 square miles with a 1.5 mile radius. Big Difference! And people living within 1 mile of Davis Drive were reassigned to Laurel Park because of capacity issues.

For that matter, if two schools are 3 miles apart from each other there will be some overlap.

No there will not be any overlap. Two circles, each with a radius of 1.5, whose centers are a distance of 3 from each other, will only intersect in at one point. And a point, by definition, has no area. Another math (i.e. geometry) error.

Finally, you did not challenge the fact that if you assume that only 16.5% of Cary's population is school age, then Cary is headed for a massive influx of ES aged children in the next 5 years, which will further erode the ability of WCPSS to make the guaranteed assignments in the Alves plan.

And you did not challenge Raleigh's reported density. It is more than your calculated density for Cary, which goes against your claim that Cary is the densest city in the county. BTW I do think that Cary is the densest city in the county, which would imply that it's density is greater than Raleigh's reported residential density of 2988.
 

Given I'm effectively assignment neutral, I disagree with some of your premise.  If the students are at or above expected achievement, it undercuts any need to assign students to any specific school -- comes back to make all schools into good schools and assignment becomes largely irrelevant.   

There are likely some who support the diversity policy only as it existed in prior to Jan 2010.   But I think there are a large group of people who have concerns about the creation of high poverty, mostly minority schools like Walnut Creek under a neighborhood and potentially any community/zone model who would be thrilled if WCPSS was effective in improving and maintaining achievement in high poverty, mostly minority schools regardless of assignment.    There is a concern which goes largely unheeded as to whether WCPSS is capable of doing this given it has been a struggle some many other places in the nation.   Show everyone it isn't a problem here in WCPSS and the issue is addressed, the concern alleviated.   Try telling everyone it can't be worse in an underachieving neighborhood school(s) with only a calendar option choice and that WCPSS will work on improving achievement at some time point in the future,  -- that tends to increase resistance, not alleviate concern.  It leaves the choices for the neighborhoods around these schools as what everyone currently has now (with or without busing as the picture is muddled now which isn't working) or what each parent with this concern knows hasn't worked in the past and isn't really working anywhere else.  Add in telling everyone WCPSS has no real solutions to implement that aren't years off in helping improve things for our children and why wouldn't everyone with this view be upset, diversity or no diversity?   Would suggest that no one discount these individuals or try to dump all "diversity supporters" into one single viewpoint.

Fox Road is a great one to use as a theoretical example as the school is already Title 1, is receiving interventions which are undergoing evaluation but which has no additional programs proposed for addition and is now at a point of also being required to give parents/students assigned there additional choices.  

A couple of things. Clearly you don't like the recent system of trying to balance poverty. I think you are projecting that system onto the new one when they are not the same. First of all, achievement never trumps proximity in Alves plan. If there is space available any student within 1.5 miles of a school regardless of achievement level should be able to get in.

The three administrative areas are already balanced but not identical. The fifth grade achievement levels for  level 1 and 2 (EOG Scores): District 25.2  Area 1 -  28.4, Area 2  - 29.9 and
Area 3 - 18.4. All the areas are within a range of the district average but not each other. Each transition grade (k, 6 and 9) would mirror the area it is in within a agreed upon range. It could be 10 or even 20 percent different if that is what the board agreed to. So one school may have 9.9 % of its students at level 1/2 but another school in the same area may have 49.9% of its students at level 1/2. Of course the plan doesn't specifically say this, but it is definitely one of the parameters the board would need to set. You can look at other choice plans in Boston or Cambridge. Controlled choice plans do not eliminate high poverty or racially isolated schools because most people choose their closets school which usually have the same demographics as themselves.

Additionally I do not believe feeder patterns will all be proximate patterns. Magnet programs should feed into each other. Therefore Millbrook ES, Douglas and Bugg which are both Creative Arts and Science ES Programs should feed to E. Millbrook. With E. Millbrook being a magnet 40% of seats should be set aside for applicants. Therefore Fox Rd. would feed to Wakefield and it would be logical and okay. A public school should welcome every student regardless of home address.