Penelope-  I found this email from a few months ago, and would like to let you know that NJT uses CTPP 3 year data to show broad county to county flows for Trans-Hudson transit planning.  We used the 2006-08 data to show trends since 2000 in where commuting to Manhattan and other key areas has changed. We also saw that there was a shift to bus and rail commuting, vs. auto for this market in most counties.  The 3 year is helpful for understanding broad trends, and specific changes. I noticed with the 5 year flow data at the county level that we saw changes related to the Great Recession. Since the 5 year data has the 3 year data imbedded as part of the 5 year data, I have looked at the difference between the 5 year and 3 year data to surmise changes between 2008 and 2010. I know statistically this may not be totally accurate, but we have seen a drop in total work trips from some counties from the 3 year to the 5 year data, and some increases in others. The numbers made sense because close in, more urban counties still increased the number of work trips to Manhattan, while mostly further out areas which were hit hard in the recession by defaults, and aging population showed a decline compared to 3 year data, but still an increase compared to 2000.  


The new procedure to make CTPP continue as a research project is a good one. Also I am happy to see Light Rail will be tested for inclusion in the Census. I brought this up back in 2007/2008 with Elaine Murakami of FHWA who was supportive, but we could not get FTA interested.  I had and extensive conversation and email exchange with FTA on this issue (Ken Cervanka), and was involved in an online debate on this.  My understanding is that the census will not allow an increase in the number of modes, but will allow Light Rail to be added. The issue was how do you classify all of the other modes, and my point was that railroad should be changed to commuter or regional rail (including Intercity), then there was bus; Light rail , Trolley, or streetcar; subway or elevated; and then Ferry I believe.  Can you tell me of the status of when Light Rail will be tested, and also how it will be shown, as a separate mode, or with trolley or streetcar (which is where it belongs in my opinion).   Some of the federal types wanted streetcar as a separate mode, which I did not believe made sense given its small amount of ridership, and also the fact that its more like light rail and Light Rail is much bigger in usage.   Thanks for any information you can provide.


Thomas Marchwinski

Senior Director, Forecasting and Research

NJ Transit, Newark, NJ


From: [] On Behalf Of Weinberger, Penelope
Sent: Tuesday, February 12, 2013 10:54 AM
Subject: Re: [CTPP] County Commuting Flows


As Liang said, the next CTPP is due in mid 2013.  It will be based on five year ACS from 2006 – 2010 and include small area data. 


In answer to the larger question; the CTPP program at AASHTO was recently transformed to an ongoing technical services program.  As you rightly point out, this follows the change at CB to an ongoing survey methodology.  The CTPP is historically user directed and wishes to continue to be so.  So I have two things to throw out there:

                One, please share the value of the program with your decision makers – when we come for funding, help them get to yes!

                Two, please let me know how you have used the three year data and if it is useful to have along with the planned five year data – the difference between the sets is the three year is more frequent, while the five year covers all geography.




Penelope Z. Weinberger

CTPP Program Manager






From: [] On Behalf Of Estersohn Dan
Sent: Sunday, February 10, 2013 9:55 PM
Subject: [CTPP] County Commuting Flows


Is there any information about production of the CTTP or the county-to-county commuting flows more than once every ten years?  Since they are based on the annual ACS there is an opportunity for more frequent updates than in the past.  What are the current plans? 


Dan Estersohn

Senior Demographer

    Arbitron Inc

    9705 Patuxent Woods Drive

    Columbia, MD  21046