The rounding within the CTPP data can play heck with doing any data
analysis. In the Chicago Central Area there are 155 individual TAZs.
If you take a simple table from Part 2, say mode to work by sex, some
interesting things happen. If you sum the total workers using the
"total" field you get 631,999. This becomes an important number because
people like to know the total. However, when you sum all the modes by
zone you get 631,883. This is not a big deal except if you want to show
drive alone, carpool, transit and other with their modal share
percents. In this region, some of us like to see the actual numbers
along with the percents. Logic would say to use the 631,883 when
calculating the percentages but then that means the sum of the totals
(which we know to be the better number because row rounding was applied
to the tables) 631,999 gets tossed aside. One could get creative and
distribute the 116 workers in some weighted fashion which would not
likely affect any percentages but then the next guy who comes along
using the CTPP data and software would get different numbers and we are
back splitting hairs over who got what number from where.
Are others finding the issue of rounded numbers a bit frustrating,
especially when it comes to aggregating TAZs?
I suppose one way to deal with this would be to simply round everything
to the nearest 100Even the 1980 and 1990 data like it appears Chuck
Purvis, MTC, has done with his Commuting to Downtown trend analysis.
http://www.mtc.ca.gov/whats_happening/press_releases/rel263.htm
--
Ed Christopher
Planning Activities
Resource Center
Federal Highway Administration
19900 Governors Drive
Olympia Fields, Illinois 60461
708-283-3534 (V) 708-574-8131 (cell)
708-283-3501 (F)
This message is for MPO and state DOTs:
This week CD-Roms containing CTPP Part 2 software and data for 16 states
were mailed out. They include:
Arizona
Colorado
Connecticut
Delaware
Illinois
Iowa
Maine
Massachusetts
Minnesota
New Hampshire
New Mexico
Pennsylvania
Rhode Island
Texas
Vermont
West Virginia
Wisconsin
We anticipate mailng out the remainig 14 states next week.
Clara Reschovsky
There are two newsworthy items related to the Census Public Use
Microdata Data.
1. The first is the recent release of the PUMS DVD. This DVD includes
the entire U.S. dataset for the 1-percent and 5-percent PUMS, and
includes the Beyond 20/20 software to produce user-defined
cross-tabulations of PUMS data. This software is VERY fast and is
excellent for developing basic two-way, three-way, four-way, n-way
cross-tabulations of PUMS. (For example, to produce a California
tabulation of persons by PUMA of residence by tenure by vehicles
available by means of transportation to work took just a few seconds to
produce this four-way table....Hours to analyze, just seconds to
create!)
The DVD contains about 3.9 gigabytes of data and software, including
the national set of raw ASCII record data. You can use the Beyond 20/20
to create your own tabulations and export into various database formats,
like csv, txt, xls, dbf, wk1, wk2, etc.
The DVD costs $70.00, and is available from the Census Bureau at:
http://www.census.gov/mp/www/Tempcat/C2KPUMS.html
2. There was a message on the Investigative Reporters & Editors'
Census listserv, from Professor Steve Doig of Arizona State University,
on some Microsoft Access code that Mr. Dick O'Reilly of the Los Angeles
Times is making available. From Prof. Doig: "It's been a while since I
put anything new on my "Reporting Census 2000" site. But Dick O'Reilly
of the LA Times has gifted us with a PUMS tutorial, complete with import
specs and sample data and queries, that he put together for those
unfamiliar with the oddities of PUMS."
Go to this page, and follow the navigation bar to What's New:
http://cronkite.pp.asu.edu/census/
This is an excellent "how-to" Census site, and has some great
information for non-journalists, as well.
The MS-Access "PUMS Tutorial" was uploaded 2/10/04. (Please don't ask
me about MS-Access or how this works. I have Access on my machine, but I
use SAS as my workhorse software to process PUMS data....)
Hope this helps,
Chuck Purvis, MTC
**************************************************************
Charles L. Purvis, AICP
Principal Transportation Planner/Analyst
Metropolitan Transportation Commission
101 Eighth Street
Oakland, CA 94607-4700
(510) 464-7731 (office)
(510) 464-7848 (fax)
www: http://www.mtc.ca.gov/
Census WWW: http://www.bayareacensus.ca.gov/
**************************************************************
I am pretty sure there is no mention of average trip length in the Journey to Work Trends Report. The average one-way commute trip is 12.2 miles according to the 2001 National Household Travel Survey.
Thanks
Nanda Srinivasan
-----Original Message-----
From: Shea, Sam J. [mailto:S.Shea@cedar-rapids.org]
Sent: Monday, February 09, 2004 5:45 PM
To: ctpp-news(a)chrispy.net
Subject: RE: [CTPP] Average Miles to Work
You could try an FHWA publication entitled "Journey to Work Trends in the
United States and its Metropolitan Areas 1960-2000".
Publication # FHWA-EP-03-058
Sam J. Shea
Long Range Planning Coordinator
City of Cedar Rapids
Development Department
50 Second Ave. Bridge, 6th floor
Cedar Rapids IA. 52401
ph:(319)286-5042 fax:(319)286-5141
Everything in life is somewhere else, and you get there in a car. -E.B.
White
> -----Original Message-----
> From: Estersohn Dan [SMTP:Dan.Estersohn@arbitron.com]
> Sent: Monday, February 09, 2004 4:06 PM
> To: ctpp-news(a)chrispy.net
> Subject: [CTPP] Average Miles to Work
>
> We are working on a project that requires a U.S.-level average miles to
> work number. Is there a source for this statistic? We would need it to
> be as recent as possible.
>
> Thanks, in advance, for your help.
>
> Dan Estersohn
> Arbitron Inc
> << File: ATT11722.txt >>
_______________________________________________
ctpp-news mailing list
ctpp-news(a)chrispy.net
http://www.chrispy.net/mailman/listinfo/ctpp-news
I used the NHTS on-line table generator to run these numbers for you. The trip purpose (1990 NPTS definition of TO AND FROM work) was used and applied to the 2001 NHTS. This is a different definition from decennial Census journey-TO-work. So, I also ran the travel time, with the 2001 results nationwide being 23.5 minutes. From decennial census, we get 25.5 minutes for journey-to-work in 2000. You can use the NHTS on-line table generator to examine distributions of trip lengths and trip durations by trip purpose. http://nhts.ornl.gov/2001/index.shtml
Elaine Murakami, FHWA Office of Planning; 206-220-4460
2001 NHTS
Average Person Trip Length (miles, Travel Day)
Where worker = '1'
(Continued)
TD Person Trip Length
Sample Size
Mean
1990 NPTS trip purpose
35,658
12.21
To/From Work
Work-Related Business
6,959
30.24
Shopping
25,449
7.29
Other Family/Personal Business
32,559
7.46
School/Church
6,600
7.80
Medical/Dentral
2,338
11.04
Vacation
738
45.12
Visit Friends/Relatives
7,942
18.15
Other Social/Recreational
22,250
9.35
Other
746
19.47
N/A
460
89.97
Refused
9
6.14
All
141,708
11.25
Average Person Trip Duration (minutes, Travel Day)
Where worker = '1'
(Continued)
TD Person Trip Duration
Sample Size
Mean
1990 NPTS trip purpose
35,638
23.50
To/From Work
Work-Related Business
6,951
33.46
Shopping
25,337
15.16
Other Family/Personal Business
32,337
15.87
School/Church
6,612
17.10
Medical/Dentral
2,342
21.29
Vacation
736
61.88
Visit Friends/Relatives
7,867
27.11
Other Social/Recreational
22,127
20.84
Other
747
34.76
N/A
479
49.22
Refused
9
14.61
All
141,182
20.58
-----Original Message-----
From: Estersohn Dan [mailto:Dan.Estersohn@arbitron.com]
Sent: Mon 2/9/2004 5:06 PM
To: ctpp-news(a)chrispy.net
Cc:
Subject: [CTPP] Average Miles to Work
We are working on a project that requires a U.S.-level average miles to work number. Is there a source for this statistic? We would need it to be as recent as possible.
Thanks, in advance, for your help.
Dan Estersohn
Arbitron Inc
You could try an FHWA publication entitled "Journey to Work Trends in the
United States and its Metropolitan Areas 1960-2000".
Publication # FHWA-EP-03-058
Sam J. Shea
Long Range Planning Coordinator
City of Cedar Rapids
Development Department
50 Second Ave. Bridge, 6th floor
Cedar Rapids IA. 52401
ph:(319)286-5042 fax:(319)286-5141
Everything in life is somewhere else, and you get there in a car. -E.B.
White
> -----Original Message-----
> From: Estersohn Dan [SMTP:Dan.Estersohn@arbitron.com]
> Sent: Monday, February 09, 2004 4:06 PM
> To: ctpp-news(a)chrispy.net
> Subject: [CTPP] Average Miles to Work
>
> We are working on a project that requires a U.S.-level average miles to
> work number. Is there a source for this statistic? We would need it to
> be as recent as possible.
>
> Thanks, in advance, for your help.
>
> Dan Estersohn
> Arbitron Inc
> << File: ATT11722.txt >>
We are working on a project that requires a U.S.-level average miles to work
number. Is there a source for this statistic? We would need it to be as
recent as possible.
Thanks, in advance, for your help.
Dan Estersohn
Arbitron Inc
Very late last week week I picked up this email form Phil Salopek
regarding the distribution of Part 2. Things are starting to roll.
-----Original Message-----
From: phillip.a.salopek(a)census.gov
We did not get as many states shipped this week as we had hoped, because
people in the office doing the duplication were off due to the weather
and our mail service was suspended because of the ricin incident. But as
of today we've sent 9 CDs with 22 states. We could very possibly finish
the distribution next week. Here's what has gone out so far.
January 29, 2004
CA and NV
IN and MI
NY and NJ
OH and KY
January 30, 2004
GA, SC and TN
ID, OR, UT and WA
February 5, 2004
IL and IA
FL
DC, MD, NC and VA
All,
I am having a heck of a time finding a list of all 1980 U.S. urbanized
areas with their population and land area. Can anyone out there help
me?
Thanks.
Bill Barker, AICP
The 1970 Census used "private auto-driver" and "private auto-passenger"
as transportation modes to work versus "drive alone" and "carpool." Does
anyone know whether private auto-driver includes only SOVs? The term
implies that it could include those who drive, but were part of a
carpool. The Census book I have does not define the terms. Thank you.
Bill Schaefer
Madison (WI) Area MPO
