Monday, 14 September 2015

US MSAs urban vs suburban growth - Raleigh and the Inland Empire

In part 6 of this series, I found that, out of the 1,000,000+ population MSAs, Raleigh and the Inland Empire experienced the most urban core growth relative to the size of their metro areas.

This is a bit surprising, because neither city is particularly well known for urban infill. These two cities were then mostly followed by the "usual suspects" of DC, Portland, Seattle, Boston, Miami and New York.

One main goal of all these comparisons was to see if I could devise a set of consistent rules to compare urban cores by, which would match relatively closely what people might subjectively view as the cores of those cities.

In the case Inland Empire, the boundaries of the urban cores seem reasonable at first glance, so how come the core is growing so fast and yet does not get much attention for urban growth? The Inland Empire is a collection of population centers inland from Los Angeles, with loose ties to LA. It has seen its Hispanic population grow significantly, perhaps in part as a result of lack of space/affordability in LA. Hispanic households are on average larger than non-Hispanic households, so I decided to see if the Inland Empire's urban core saw an increase in household sizes.

Stats for the Inland Empire's urban core

So, whatever the cause, household size increases have been the main driver of population growth in the urban core. This is in contrast with most other urban cores, where household sizes decreased slightly. If the Inland Empire experienced a slight decrease in household sizes like most other urban cores, the urban core population growth would have still been above average, but probably not in the top 10 and certainly not #2.

How about Raleigh?

The growth wasn't due to household size increases, which stayed more or less constant.
Some of the growth was at the southern edge of the city. It's greenfield development, so not true infill, but was relatively close to the core, allowing the census tracts that contained them to meet the mode share/density criteria. New subdivisions are highlighted in white, with the white lines showing the boundaries of the census block groups that contain them.

Here's an example of a typical subdivision
Although lot sizes are smaller than the older suburban development beside it, it is still single family greenfield development at the periphery with an auto oriented street network.

The largest subdivision is a bit different and has some New Urbanist elements. The street network is better connected and there are townhouses mixed in with the single family homes. It's called Renaissance Park and its website advertises proximity to the urban amenities of Downtown Raleigh, though it assumes residents will drive there. There is also mention of commercial and residential properties side by side, but unless that's referring to the strip malls just outside the subdivision, I'm not sure what they're talking about. I suppose having those strip malls nearby is better than nothing though, and it ias the reason why the community has a Walkscore of about 50, instead of the <30 Walkscore typical of suburban Raleigh.
All in all, the census block groups that contain these greenfield developments saw their population grow by 5,597, out of the 15,236 population increase in Raleigh's "urban core". That leaves 9,639 in population growth that could be described as resulting from infill. This would cause Raleigh to drop to a still quite respectable #4 for urban core population increase relative to MSA size.

So what does this infill look like? Here are the census block groups ranked by population growth.

1. The North Carolina State University Campus saw its population increase by 1582. The only residential development that seems to have taken place there is the Wolf Village student residences, circled below.

2. Downtown Raleigh grew by 976 people. There are a few smaller apartment and townhouse developments, but these two midrises seem to be the biggest new construction residential developments (based on historical aerial comparisons).

3. The census block group that grew the next fastest was in northern Raleigh, growing by 785 people, mostly as a result of these auto-oriented townhouse and lowrise apartment infill developments.

4. Next is a block group in Cary that grew by 610 people, the main development seems to have been the townhouses in the centre of this image. That's not enough to account for the entirety of the population increase, so household sizes must have gone up as well.

5. In the census block group with the 5th most growth, the infill has mostly been townhouse and apartment complexes, although there was also one cul-de-sac of SFHs (not shown). There are some offices just to the north, and some shopping centres north of those, about a 15min walk away. This block group grew by 582 people.

6. Then there's another block group in North Raleigh that grew by 505 people, with this auto-oriented apartment complex being the only noticeable new development.

7. That's followed by a block group in NE Raleigh that grew by 484 people thanks to this new townhouse complex. Since it's at least near some shopping centres, the walkscore is about 60.

8. Next, a block group in SE Raleigh that grew by 435 people. The main new development seems to be this auto-oriented infill subdivision of single family homes and lowrise apartments.
That block group also saw a few homes built on small cul-de-sacs off the old Raleigh street grid.

9. The next blog group is just next to #3 and grew by 421 people. The main new development was this auto-oriented infill subdivision of single family homes and apartments.

10. The ninth fastest growing block group was just west of downtown Raleigh, around the North Boylan neighbourhood, growing by 415 people. The growth seems to have been in the form of midrises like these.

11. The next block group grew by 389 people. Most of the development has been near a cluster of auto-oriented retail and offices, consisting of a cluster of townhouses, lowrise apartments and small lot SFH (looks a bit like townhouses in the aerial). Despite the auto-oriented nature, the close proximity to these amenities still makes for a walkscore of about 60, which is well above the Raleigh average.
There's also a smaller SFH infill subdivision in a more remote setting further NE in the same block group.

12. The next census block group is in an upscale inner ring neighbourhood, and grew by 375 people. This development seems to be the main source of growth, of the two apartment buildings, the one with the small parking lot in front (on the left) has some ground floor retail.

13. This block group is in Cary, west of its town centre, and grew by 360 people, mostly thanks to this townhouse development, which was not quite complete in 2010, but appears to be in this more recent aerial.

14. The growth here (+342) was mostly the result of a townhouse development in a highly auto-oriented setting (walkscore of 9).

15. This block group is near #3 and #9. Townhouses and apartments were built in an auto-oriented setting, with the census block group growing by 323 people.

These fifteen block groups and the four fringe block groups show further up account for most of the infill group in Raleigh's "urban core". The remainder of the urban core grew by just 857 people.

Raleigh-Cary is a very suburban metropolitan area. The part of the metro area that is even remotely urban is very small, and while it is growing at a moderate pace, only a small fraction of the metro area's growth is taking place there.

Aside from that, this post shows that there is some suburban infill. While auto-oriented for now, perhaps it can help provide the density needed to support better retail and transit options that are accessible by foot. As for the growth on Raleigh's southern fringe, it is at least close to downtown, which means it can support downtown businesses, and be a short auto commute away. And the distances are short enough that getting to downtown by bus or bike would be feasible if the infrastructure is in place.

The rest of the growth, a population increase of 318,000 or 95% of the population growth, took place in census tracts that either had 2000 densities of less than 1,694 pop/sq mi, or auto commute mode share of more than 93.2%, or both.


  1. Hi Nick, I am a student at McMaster University and I follow your blog quite regularly. I was wondering, is the data you use to chart historical population changes within CMAs and MSAs publicly available? If so could you point me in the right direction, I was hoping to do some similar analysis. Thanks, Charles

  2. Most of it is, although if you're a student you might find it easier to ask some people at McMaster for GIS files, especially if you're looking to do more thorough analyses. GIS software shouldn't be too expensive if you're a student ($30?), and GIS/geography profs and librarians can probably help you find the GIS files.

    Otherwise, you can use

    For MSAs (last 3 are just 2000/2010)

    For CMAs
    2011 data (you can also use NHS profiles for other additional demographic stats):
    2006 data

    2001 data I don't think is publicly available in map form, but you can get census tract data here
    And use the map from here to help find the location of the census tract

    1991 census tract profiles
    census tract maps

    And then for older Canadian CMA data, if you go to and do a search for "city name year census tracts" you should be able to find census tract data and maps.

    Census tract data only goes back to 1940/1941, and for some of the smaller CMAs and MSAs, census tracts were only delineated as late as 1960 (or even 1970 for some American CMAs). For earlier data you'll need ward level data, which is harder to find.

  3. This is great instruction. Thanks so much Nick. I do have a copy of Arc GIS which I will conduct my analysis with. Mainly I was having trouble finding the older CMA data around the 40-60s era. I will look through and hopefully I can tract down the data there. Thanks again. Charles

  4. It shouldn't be too hard to find, ex:

    However I'm not sure if CMA data exists for the smaller cities during the 40s and 50s. You should be able to find data put together for the 1961 census for most cities though, which will also have the 1956 population counts.