Category: Government

The effects of TOD bonuses versus what a transit overlay district could do

December 19, 2014 / / 2 Comments

I responded to Carter O’Brien’s comment on an EveryBlock discussion about a gentrification series on WBEZ, Chicago’s National Public Radio affiliate. I reposted the comment here because I want to talk about the problems of piecemeal zoning and how the city’s TOD ordinance can be improved to generate more and diverse housing types (by types I’m talking about quantity of units and stories, not rent vs. own).

@Carter: I think we might be on the same page about something. You wrote:

The question becomes to what degree should zoning be used to encourage one form of land use over another. That’s the tool in the City’s toolbox, so to speak.

Substantial zoning bonuses which will create brand new high rise towers in a neighborhood of lower-density historic architecture will encourage the settling of one economic class of people and the removal of another. [snip] The evidence is that we see shrinking populations of lower-middle class people raising families by the L stops in Wicker Park, Bucktown, Old Town, Lincoln Park and Lake View.

[Actually, pause now and go read Carter’s full comment – he mentions teardowns as an issue that should be part of a gentrifying neighborhood discussion.]

I like that the TOD ordinance seems to be fueling proposals to build many units near transit stations, but it may be building more many units than the community prefers.

I’d like to see transit-oriented zoning also used as a tool to also spur smaller, multi-unit buildings (two flats, three flats, four flats, courtyard buildings) by perhaps preventing low-density buildings so close to transit.

Across from Goethe Elementary School a huge parcel of land is being turned into 7 single-family homes on Medill Ave. That’s great land near a good school and 3 blocks from the California Blue Line station.

Zoning could have been used to require 2-4 unit buildings so that more families have a chance of benefiting from that location but instead the zoning district here makes building 2-4 unit residences on those parcels illegal.

A “transit overlay district” would be something new to Chicago and could do away with the piecemeal zoning of differing densities, one right next to or mixed in with the other. You might see Bx-1 next to Cx-2 and then a Rx-4. Create concentric zoning circles that keep the density uniformly high nearest the train station and then drop off the further away you get.

zoning districts around the California Blue Line station

This map includes the California Blue Line station and the Goethe school houses (empty area northwest of the RM-5 zone on Medill Avenue). The school is outlined inside PD 349.

Quick zoning primer

  • Adapted from Second City Zoning’s plain-English zoning district descriptions.
  • B = retail and apartments above
  • C = commercial (more business types than B) and apartments above
  • RS = single-family homes only
  • RT = 2-4 flats, single-family allowed
  • RM = multi-unit, single-family allowed

The -x number of a district indicates the density allowed (this works for single-family homes, too, setting the minimum parcel area upon which the house is built).

Note: This post has slightly different text from my EveryBlock comment because I had to edit that one for length (the site accepts 2,000 characters maximum).

Working with ZIP code data (and alternatives to using sketchy ZIP code data)

December 17, 2014 / / 5 Comments
1711 North Kimball Avenue, built 1890

This building at 1711 N Kimball no longer receives mail and the local mail carrier would mark it as vacant. After a minimum length of time the address will appear in the United States Postal Service’s vacancy dataset, provided by the federal Department of Housing and Urban Development. Photo: Gabriel X. Michael.

Working with accurate ZIP code data in your geographic publication (website or report) or demographic analysis can be problematic. The most accurate dataset – perhaps the only one that could be called reliably accurate – is one that you purchase from one of the United States Postal Service’s (USPS) authorized resellers. If you want to skip the introduction on what ZIP codes really represent, jump to “ZIP-code related datasets”.

Understanding what ZIP codes are

In other words the post office’s ZIP code data, which they use to deliver mail and not to locate people like your publication or analysis, is not free. It is also, unbeknownst to many, a dataset that lists mail carrier routes. It’s not a boundary or polygon, although many of the authorized resellers transform it into a boundary so buyers can geocode the location of their customers (retail companies might use this for customer tracking and profiling, and petition-creating websites for determining your elected officials).

The Census Bureau has its own issues using ZIP code data. For one, the ZIP code data changes as routes change and as delivery points change. Census boundaries needs to stay somewhat constant to be able to compare geographies over time, and Census tracts stay the same for a period of 10 years (between the decennial surveys).

Understanding that ZIP codes are well known (everybody has one and everybody knows theirs) and that it would be useful to present data on that level, the Bureau created “ZIP Code Tabulation Areas” (ZCTA) for the 2000 Census. They’re a collection of Census tracts that resemble a ZIP code’s area (they also often share the same 5-digit identifiers). The ZCTA and an area representing a ZIP code have a lot of overlap and can share much of the same space. ZCTA data is freely downloadable from the Census Bureau’s TIGER shapefiles website.

There’s a good discussion about what ZIP codes are and aren’t on the GIS StackExchange.

Chicago example of the problem

Here’s a real world example of the kinds of problems that ZIP code data availability and comprehension: Those working on the Chicago Health Atlas have run into this problem where they were using two different datasets: ZCTA from the Census Bureau and ZIP codes as prepared by the City of Chicago and published on their open data portal. Their solution, which is really a stopgap measure and needs further review not just by those involved in the app but by a diverse group of data experts, was to add a disclaimer that they use ZCTAs instead of the USPS’s ZIP code data.

ZIP-code related datasets

Fast forward to why I’m telling you all of this: The U.S. Department of Housing and Urban Development (HUD) has two ZIP-code based datasets that may prove useful to mappers and researchers.

1. ZIP code crosswalk files

This is a collection of eight datasets that link a level of Census geography to ZIP codes (and the reverse). The most useful to me is ZIP to Census tract. This dataset tells you in which ZIP code a Census tract lies (including if it spans multiple ZIP codes). HUD is using data from the USPS to create this.

The dataset is documented well on their website and updated quarterly, going back to 2010. The most recent file comes as a 12 MB Excel spreadsheet.

2. Vacant addresses

The USPS employs thousands of mail carriers to delivery things to the millions of households across the country, and they keep track of when the mail carrier cannot delivery something because no one lives in the apartment or house anymore. The address vacancy data tells you the following characteristics at the Census tract level:

  • total number of addresses the USPS knows about
  • number of addresses on urban routes to which the mail carrier hasn’t been able to delivery for 90 days and longer
  • “no-stat” addresses: undeliverable rural addresses, places under construction, urban addresses unlikely to be active

You must register to download the vacant addresses data and be a governmental entity or non-profit organization*, per the agreement** HUD has with USPS. Learn more and download the vacancy data which they update quarterly.

Tina Fassett Smith is a researcher at DePaul University’s Institute of Housing Studies and reviewed part of this blog post. She stresses to readers to ignore the “no-stat” addresses in the USPS’s vacancy dataset. She said that research by her and her colleagues at the IHS concluded this section of the data is unreliable. Tina also said that the methodology mail carriers use to identify vacant addresses and places under change (construction or demolition) isn’t made public and that mail carriers have an incentive to collect the data instead of being compensated normally. Tina further explained the issues with no-stat.

We have seen instances of a relationship between the number of P.O. boxes (i.e., the presence of a post office) and the number of no-stats in an area. This is one reason we took it off of the IHS Data Portal. We have not found it to be a useful data set for better understanding neighborhoods or housing markets.

The Institute of Housing Studies provides vacancy data on their portal for those who don’t want to bother with the HUD sign-up process to obtain it.

* It appears that HUD doesn’t verify your eligibility.

** This agreement also states that one can only use the vacancy data for the “stated purpose”: “measuring and forecasting neighborhood changes, assessing neighborhood needs, and measuring/assessing the various HUD programs in which Users are involved”.

Morgan CTA station ranks highly in rail system for building permits

August 13, 2014 / / 0 Comments
Let Your Conscious Be Your Guide

The gutted cold storage warehouse in the background is within a quarter mile of the Morgan CTA station. Photo by Seth Anderson.

Excluding all of the Chicago Transit Authority stations in the central business district you’ll find that the new Morgan station ranks highly in the number of building permits issued within a quarter mile. It has a top spot when you calculate those permits’ estimated project costs. The CTA recently discussed with DNAInfo the results of a preliminary study it conducted that showed how the Morgan station is at the center of a lot of construction growth in the West Loop/Fulton Market area, and a contributing factor to this growth.

Now that Licensed Chicago Contractors shows you the two nearest CTA and Metra rail stations to each building permit, and I’ve become well-versed in writing PostGIS queries on the fly, I wrote a query that lists the CTA stations with the most building permits within a quarter mile (“nearby”).

First, though, let’s count how many stations don’t have permits nearby. With the query at the bottom you get a list of station names, the number of permits nearby, and a sum of the estimated costs of those permits sorted by the number of permits. Since I used a “LEFT JOIN” I also get a count of all the permits (the table on the LEFT) that don’t have a match with CTA stations (the table on the right).

There are 127 rows returned and a previous count of the table told me there are 145 stations, including ones outside the Chicago city limits. (There are stations in Cicero, Wilmette, Evanston, Rosemont, Oak Park, Forest Park, and Skokie.) The first row represents NULL, or all of the stations that don’t have permits nearby. That leaves me with 126 rows and 19 stations without permits, or 19 stations outside the City of Chicago.

I verified this by eyeballing it. I looked at a map and counted roughly 19 stations that wouldn’t have the 1/4 mile overlap with a Chicago building permit. The two Austin stations, on the Blue Line Forest Park branch and the Green Line Oak Park branch, are near Chicago and also showed up as a discrete station in the query results. Austin on the Blue Line was dead last, actually!

Let’s get back on track and look at Morgan now. I don’t think it’s fair to compare the Morgan station area with an expected, higher-activity area like the Loop and Central Business District so I eyeballed the list and started the #1 ranking with the first station outside the CBD.

  1. Armitage (Brown, Purple Express) is the station outside the CBD with the most building permits nearby.
  2. Damen-Milwaukee (Blue)
  3. North/Clybourn (Red)
  4. Addison (Red)
  5. Morgan (Green, Pink)

There you have it, from 2009 to today, the Morgan station had the fifth highest number of building permits outside of the Chicago Central Business District. It beat Fullerton (Red, Brown, Purple) in Lincoln Park, and Roosevelt (elevated and subway combined) in the South Loop. The station’s construction began in 2010 and the grand opening occurred May 24, 2012. During this period Morgan had the second highest amount of aggregated estimated costs at $199,911,953.00, behind North/Clybourn, at $218,118,037.37.

Take this analysis with several grains of Morton salt, though, because the following caveats are important to consider: building permits are really speculative development; much of these may be for kitchen renovations or porch reconstructions; I didn’t look up when it was “for sure” that the station was being built so I don’t know when developers would have become interested.

Looking at a longer period

I will, however, run a few more queries to find how Morgan’s position changes, starting with expanding the query to “all time” data (really the end of 2006 to today). It turns out that when looking through all available years Morgan’s position remains at #5 but other stations change position.

  1. Fullerton
  2. Armitage
  3. Damen-Milwaukee
  4. Addison
  5. Morgan

During this period, which covers the end of 2006 until today, Morgan had the highest aggregated estimated costs of the above five stations, at $236,707,083.00. It beat Fullerton’s amount of $160,825,680.30.

Looking only at “new construction”

Since these include all permit types, including water heater installations and window replacements, it doesn’t give us a good look at economic expansion in the areas surrounding CTA stations. I’ve filtered the data so only “new construction” building permits come through. I’m still interested in stations outside the CBD. Here’s how Morgan performed when looking at purely the quantity of new construction permits issued from 2009 to today:

  1. Armitage, 46 new construction building permits
  2. Southport, 38
  3. Addison (Red), 34
  4. North/Clybourn,
  5. Wellington,
  6. California-Milwaukee,
  7. Belmont (Red)
  8. Ashland (Green, Pink)
  9. Irving Park (Brown)
  10. Fullerton
  11. Damen (Brown)
  12. Division-Milwaukee
  13. Western-Milwaukee
  14. Ashland (Orange)
  15. Damen-Milwaukee
  16. Western-Congress
  17. Paulina
  18. Addison (Brown)
  19. Diversey
  20. Sedgwick
  21. Loyola
  22. Montrose (Brown)
  23. Sox-35th-Dan Ryan
  24. Morgan, 13 new construction building permits

Let’s remove that date filter and look at the whole building permits period of late 2006 to today.

  1. Southport (Brown Line), 80 new construction permits, all-time
  2. Armitage (Brown, Purple), 72
  3. Western-Congress (Blue), 66
  4. Addison (Red), 64
  5. Belmont (Red, Brown), 63
  6. Western-Milwaukee, 59
    Damen-Milwaukee, 59
  7. North/Clybourn, 55
    Diversey, 55
  8. Division-Milwaukee, 53
  9. Sox-35th-Dan Ryan, 51
  10. Wellington, 50
  11. 35-Bronzeville-IIT, 48
  12. Irving Park (Brown), 44
  13. Morgan, 43 new construction permits

Now switching the order method around and Morgan appears better when you look at aggregated estimated costs, from 2009 to today.

  1. Illinois Medical District, $236,020,000.00
  2. North/Clybourn, $172,373,335.00
  3. Loyola, $161,744,075.00
  4. Polk, $106,000,000.00
  5. Grand-Milwaukee, $77m224,500.00
  6. Wellington, $72m802,300.00
  7. Belmont (Red), $71,300,302.00
  8. Morgan, $68,300,800.00

Last query – remove the data filter and look at aggregated costs for the whole building permits period where Morgan maintains a top 10 position.

  1. North/Clybourn, $277029045.00
  2. Illinois Medical District, 236,020,000.00 (same as 2009 to today period)
  3. Polk, $188,794,975.00
  4. Loyola, $185,444,075.00
  5. Belmont (Red), $1635,00,085.00
  6. Fullerton, $129,444,051.00
  7. Wellington, $111,335,051.00
  8. Granville, $99,356,702.00
  9. Morgan, $83,995,800.00

The data I’d really like to have, though, is sales tax receipts for the same years. 

This is not a valid PostgreSQL query. The brackets indicate the options I was using to retrieve the above results. The geometries are in or transformed to EPSG 3435 (Illinois StatePlane East Feet) and 1,320 feet is a quarter mile.

SELECT
 COUNT (P .permit_) AS count,
 MIN (C .longname) as name,
 min(lines) as lines, 
 sum(_estimated_cost) as sum
FROM
 permits P left join
 stations_cta C
ON
 ST_DWithin (
  ST_Transform (P .geometry, 3435),
  C .geom,
  1320
 )
[WHERE] [EXTRACT (YEAR FROM issue_date) >= 2009] [_permit_type = 'PERMIT - NEW CONSTRUCTION']
GROUP BY
 C .gid
ORDER BY
 [count,sum] DESC

Chicago wards with the most landmarked places

June 24, 2014 / / 0 Comments
Montgomery Ward Complex

People float by the Montgomery Ward Complex on Kayaks. Photo by Michelle Anderson.

Last week I met with the passionate staff at Landmarks Illinois to talk about Licensed Chicago Contractors. I wanted to understand the legality for historic preservation and determine ways to highlight landmarked structures on the website and track any modifications or demolitions to them.

I incorporated two new geographies over the weekend: Chicago landmark districts, and properties and areas on the National Register of Historic Places (both available on the City of Chicago open data portal).

I used pgShapeLoader to import them to my DigitalOcean-hosted PostgreSQL database and modified some existing code to start looking at these two new datasets. Voila, you can now track what’s going on in the Montgomery Ward Company Complex – currently occupied by “600 W” (at 600 W Chicago Avenue) hosting Groupon among other businesses and restaurants.

Today I was messing around with some queries after I saw that the ward containing this place on the National Register – the 27th – also had a bunch of other listed spots.

I wrote a query to see which wards have the most places on the National Register. The table below lists the top three wards, with links to their page on Licensed Chicago Contractors. You’ll find that many have no building permits associated with them. This is because of two reasons: the listing’s small geography to look within for permits may not include the geography of issued permits (they’re a few feet off); we don’t have a copy of all permits yet.

[table id=15 /]

4 wards don’t have any listings on the National Register of Historic Places and nine wards have one listing.

Bike lane mileage is the wrong metric for your city to publicize

May 28, 2014 / / 8 Comments

Sometimes I tweet things that get pretty popular and then I need to go into more details. Case in point:

Which I followed by tweeting:

Knowing how many miles of bike lanes you have has little importance in determining if I’m going to bike in your city when I visit, or if I’m considering moving there, or if I want to add you to a “bicycle friendly cities” list.

What’s more important is how much the number of people bicycling on those bike lanes has changed. This number will reflect the quality of your bike lanes. Are they still in good shape or have they faded a lot? Do they connect to each other to create a network, or are there gaps that increase the stress of a route? How have you treated the bike lane at intersections, the place where a conflict and crash is most likely to occur?

Chicago Tribune architecture critic Blair Kamin touched on these points in his recent critique, one of the few worthwhile articles the Tribune has published in the last year about bicycling, by interviewing an organization that tries to make it politically palatable to build unconventional – in the United States – bike lanes.

“Chicago has made incredible progress over the last few years,” said Martha Roskowski, vice president at People for Bikes, a Boulder, Colo.-based advocacy group. But, she added, “Chicago also has a ways to go.”

That’s saying it nicely.

Addressing the gaps in the city’s network of protected bike routes, Roskowski said: “People evaluate a potential bike ride on the basis of the weakest link, the scariest part of the trip, which might be a really busy road you have to ride along or across. People have tolerance for a little bit of that. But if it’s sustained or if it feels dangerous, they just won’t do it.”

Enter Close Calls, deteriorating bike lanes, bumpy pavement, and constant obstacles and you get Chicago’s ridiculously low bicycle commute to work numbers.

Since Emanuel took office in 2011, Chicago has installed 52 miles of protected bike lanes [it’s only installed 16 miles of protected bike lanes], which use a variety of means — plastic pylons, striped pavement markings and non-curbside parking spaces — to separate bikes from vehicles. That brings the city’s total bicycle lanes to 207 miles.

That’s cool that we have 207 miles. How many miles of streets without bike lanes do we have? It’s 4,000 and some change minus 207.

Why doesn’t Mayor Rahm Emanuel talk about how many people have taken up bicycling since he took office, or how many more trips Chicagoans made (and where) because of those 52 miles of new buffered and protected bike lanes?

He can’t say how many people are riding their personal bikes because the city doesn’t track this.

Conversely we can track Divvy bike-share use down to the minute and the company announced that Saturday, May 24, they had their most trips ever. Only to be eclipsed by almost 4,000 more trips on Sunday, May 25 (helped in no small part by the Bike The Drive event where people can bicycle on a Lake Shore Drive that’s closed to vehicles).

In another blow to good data for Chicago, Divvy will only be releasing trip data twice a year, while Citibike in New York City will be publishing it monthly, an improvement of Capital Bikeshare’s quarterly data releases.

If you’re not tracking who’s using your infrastructure, will you be able to know if the people you set out to attract have come out?