Bruce,
Take a look at the USDA/Economic Research Service's tract-based Rural-Urban Commuting
Areas (RUCAs). They are essentially what you've described below.
In addition, a tract-based directional commuting flow method for forming regions was one
of the alternative approaches proposed in 1998 as part of the Metropolitan Statistical
Area Review Project.
Michael Ratcliffe
Asst. Division Chief, Geographic Standards, Criteria, Research, and Quality
Geography Division
U.S. Census Bureau
Office 301.763.8977<tel:301.763.8977>
Cell 202.253.3449<tel:202.253.3449>
Michael.r.ratcliffe@census.gov<mailto:Michael.r.ratcliffe@census.gov>
census.gov<http://www.census.gov/>
Connect with us on Social
Media<http://www.census.gov/about/contact-us/social_media.html>
On Dec 11, 2016, at 2:51 PM, Bruce Spear
<BSpear@camsys.com<mailto:BSpear@camsys.com>> wrote:
I agree with Todd’s comment that the criteria used in the PLOSOME article are extreme,
resulting in some rather extreme mega-regions
It might be more reasonable to apply the Office of Management and Budget (OMB) criteria
for defining metropolitan areas but using Census Tracts instead of entire counties as the
geographical units. Under these revised criteria, the core for each “megaregion” would be
an urbanized area (population greater than 50,000), as defined by the Census Bureau.
Outlying Census Tracts would then be added to each core urbanized area as long as 25
percent of the workers living in that Census Tract commuted to a workplace Census Tract
located within the core urbanized area. Census Tracts included in each core would have to
be contiguous (i.e., no gaps or skips). And two adjacent urbanized areas could be merged
to form a single, combined core urbanized area if 25 percent of the population within the
Census Tracts of one urbanized area (as a group) commute to workplace Census Tracts in the
other urbanized area.
I suspect that the result of changing from counties to Census tracts would expand the
currently defined metropolitan area boundaries outward to portions of what are now rural
or micropolitan counties, but would not generate the extreme megaregions shown in the
PLOSOME article. You could also vary the size of the boundaries by altering the percent
population criteria, or by adding a distance or travel time criterion to limit “extreme”
commutes.
Bruce D. Spear, PhD.
Senior Associate
Cambridge Systematics, Inc.
100 Cambridgepark Drive, Suite 400
Cambridge, MA 02140
t 617-234-0417
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From: Cervenka, Kenneth (FTA) [mailto:Kenneth.Cervenka@dot.gov]
Sent: Tuesday, December 06, 2016 11:14 AM
To: ctpp-news@chrispy.net<mailto:ctpp-news@chrispy.net>
Subject: Re: [CTPP] Distance travveled to work
Hello again,
I think Todd’s question was somewhat rhetorical, but perhaps I should nevertheless note,
in hopes of avoiding any misunderstanding: my use of the words “rather awesome” was not
about any particular conclusions that were reached in the study, instead it was about the
interesting effort to visualize “commuter travel pattern” data associated with 70,000
census tracts.
Ken C.
From: ctpp-news-bounces@chrispy.net<mailto:ctpp-news-bounces@chrispy.net>
[mailto:ctpp-news-bounces@chrispy.net] On Behalf Of Graham, Todd
Sent: Monday, December 05, 2016 1:40 PM
To: ctpp-news@chrispy.net<mailto:ctpp-news@chrispy.net>
Subject: Re: [CTPP] Distance travveled to work
Ken—
The analysis you saw comes from a PLOSONE academic article. Looked at it last week. The
number crunching was done by Dash Nelson, a geographer at Dartmouth.
Dash Nelson’s paper is an exploration of: what if we used the same data Census uses for
metro area, but changed criteria, changed the parameters and cut-offs… The criteria used
are extreme, and the result is extreme.
Questions that occur to me: Do you believe Des Moines is “mega region” – or are you
instead looking at an artificial region populated by (few) people not tied in to any other
surrounding regional economy – and let’s call that Des Moines.
<image016.png>
Todd Graham
Principal Forecaster | Metropolitan Council | Regional Policy and Research
todd.graham@metc.state.mn.us<mailto:todd.graham@metc.state.mn.us>
P. 651.602.1322 | F. 651.602.1674
390 North Robert Street | St. Paul, MN 55101 |
metrocouncil.org/data<http://www.metrocouncil.org/data>
<image017.gif><image018.png><http://www.facebook.com/MetropolitanCouncil><image019.png><http://twitter.com/#!/metcouncilnews><image020.png><http://www.linkedin.com/in/toddgraham><image021.png><http://www.youtube.com/user/MetropolitanCouncil>
<image022.gif><https://public.govdelivery.com/accounts/MNORGMETC/subscribers/new?preferences=true>
From: ctpp-news-bounces@chrispy.net<mailto:ctpp-news-bounces@chrispy.net>
[mailto:ctpp-news-bounces@chrispy.net] On Behalf Of Cervenka, Kenneth (FTA)
Sent: Friday, December 02, 2016 3:41 PM
To: ctpp-news@chrispy.net<mailto:ctpp-news@chrispy.net>
Subject: Re: [CTPP] Distance travveled to work
This is a little bit off-topic, but someone sent the following to me a few minutes ago,
which is an interesting portrayal of the 2006-2010 CTPP-based travel patterns across the
country.
https://www.wired.com/2016/12/mesmerizing-commute-maps-reveal-live-mega-reg…
Well, at least I thought it looked rather awesome.
Ken Cervenka
From: Kim, Kyeongsu [mailto:kkim@louisberger.com]
Sent: Friday, December 02, 2016 2:58 PM
To: ctpp-news@chrispy.net<mailto:ctpp-news@chrispy.net>
Subject: Re: [CTPP] Distance travveled to work
I agree with Steve that LODES does not provide the distance. Find the linked document for
LODES.
https://lehd.ces.census.gov/data/lodes/LODES7/LODESTechDoc7.2.pdf
For my previous analysis, I used the centroid of census block group (you can go down to
block level) OD and estimated (transit and driving) travel time using google api.
LEHD Origin-Destination Employment Statistics (LODES
...<https://lehd.ces.census.gov/data/lodes/LODES7/LODESTechDoc7.2.pdf>
lehd.ces.census.gov<http://lehd.ces.census.gov>
2 Rev. 20160303 The geography crosswalk is a relationship file that establishes the
hierarchical connection between each 2010 census tabulation block and all higher ...
Kyeongsu (Steve) Kim
Senior Planner
direct +1.212.383.7233
mobile +1.732.425.1311
email kkim@louisberger.com<mailto:kkim@louisberger.com>
web
louisberger.com<http://www.louisberger.com/>
Louis Berger
48 Wall Street, 16th Floor | New York | NY | 10005 | USA
________________________________
From: ctpp-news-bounces@chrispy.net<mailto:ctpp-news-bounces@chrispy.net>
<ctpp-news-bounces@chrispy.net<mailto:ctpp-news-bounces@chrispy.net>> on
behalf of Steve Wilson
<swilson@srfconsulting.com<mailto:swilson@srfconsulting.com>>
Sent: Friday, December 2, 2016 3:39:34 PM
To: ctpp-news@chrispy.net<mailto:ctpp-news@chrispy.net>
Subject: Re: [CTPP] Distance travveled to work
I wonder if people are referring to the buffer tool available with the LEHD “On The Map”
tool. That is distance, but it is not travel distance.
From: Cervenka, Kenneth (FTA) [mailto:Kenneth.Cervenka@dot.gov]
Sent: Friday, December 02, 2016 2:30 PM
To: ctpp-news@chrispy.net<mailto:ctpp-news@chrispy.net>
Subject: Re: [CTPP] Distance travveled to work
Hello,
Both Kevin Tierney and Alex Karner are quite right about there not being a “distance”
table in the ACS/CTPP files.
But now this brings up an interesting secondary question: exactly how is this being
calculated in the LEHD product? Unless everyone who commutes to work drives their own car
in a mostly uncongested and non-tolled environment, this is actually a lot more
complicated to “get right” than one might think, even if a road network-based
find-the-minimum-path approach is used. I presume there is documentation about how the
distance-based calculations are being done (surely it is something more than a
straight-line between two centroids, multiplied by a national factor to represent circuity
for auto travelers, but that would be my guess), but a quick search of LEHD and LODE
documents did not reveal the answer.
Ken Cervenka
FTA Office of Planning
From: ctpp-news-bounces@chrispy.net<mailto:ctpp-news-bounces@chrispy.net>
[mailto:ctpp-news-bounces@chrispy.net] On Behalf Of Kevin Tierney
Sent: Friday, December 02, 2016 2:27 PM
To: ctpp-news@chrispy.net<mailto:ctpp-news@chrispy.net>
Subject: Re: [CTPP] Distance travveled to work
No. Some users noted a desire for it in the recent CTPP Assessment, but others indicated
they get that information from their travel models.
From: ctpp-news-bounces@chrispy.net<mailto:ctpp-news-bounces@chrispy.net>
[mailto:ctpp-news-bounces@chrispy.net] On Behalf Of Alex Karner
Sent: Friday, December 02, 2016 2:21 PM
To: ctpp-news@chrispy.net<mailto:ctpp-news@chrispy.net>
Subject: Re: [CTPP] Distance travveled to work
ACS has commute time but not distance. With CTPP you can use OD flows to calculate
distance using network approaches or assuming straight lines. No way to get distance
directly as far as I know.
-Alex
--
Alex Karner, PhD
Assistant Professor
School of City & Regional Planning
Georgia Institute of Technology
alexkarner.com<http://www.alexkarner.com/>
________________________________
From: Mara Kaminowitz
<mkaminowitz@baltometro.org<mailto:mkaminowitz@baltometro.org>>
To: "ctpp-news@chrispy.net<mailto:ctpp-news@chrispy.net>"
<ctpp-news@chrispy.net<mailto:ctpp-news@chrispy.net>>
Sent: Friday, December 2, 2016 2:07 PM
Subject: [CTPP] Distance travveled to work
Hello,
Is there a table in ACS or CTPP that gives the distance traveled to work? I know it's
in LEHD but I'd like to pin down another source.
Mara
--
Mara Kaminowitz, GISP
GIS Coordinator
.........................................................................
Baltimore Metropolitan Council
Offices @ McHenry Row
1500 Whetstone Way
Suite 300
Baltimore, MD 21230
410-732-0500 ext. 1030
mkaminowitz@baltometro.org<mailto:mkaminowitz@baltometro.org>
www.baltometro.org<http://www.baltometro.org/>
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