You don't need 2 decimal places.  The data don't support that level of precision!!!

Patty Becker


At 06:06 PM 5/20/2011, you wrote:
Don't mind Steve--he is just giving a shameless plug for the NHTS ;-)

In the ACS you can get a vehicle occupancy for people commuting to work.  It takes a little work but you can calculate it from table B8301 (mode to work).  The trick is what assumption do you use for the 5-6 people per car (maybe 5.5) cohort and the 7+ category.  In 1990 we actually knew the factor and it was around 0.3xxx.  Try a few numbers and see what you like, 7.2 people per car; 7.3, but I would not go over 7.5

Now for another shameless plug.  One of the beauties of the CTPP tabulations is that there is a vehicle occupancy table for the work commuters.  Unfortunately, with the 3-year CTPP it is only carried out to 1 decimal so everything is 1.1.  I believe the 5-year tab due out sometime in 2013 will have 2 decimal places.

Back to the NHTS, it's strength here is that it has all trip purposes.


Polzin, Steve wrote:
there is no data on occupancy only household vehicle availability.  The 2009 NHTS would have vehicle occupancy data.
From: ctpp-news-bounces@chrispy.net [ mailto:ctpp-news-bounces@chrispy.net] On Behalf Of Jim Hubbell
Sent: Friday, May 20, 2011 4:35 PM
To: ctpp-news@chrispy.net
Subject: [CTPP] private vehicle occupancy data from ACS
I'm trying to track down an estimate of private vehicle occupancy from the 2009 ACS 1-year estimates, and am having some difficulty finding the table that includes this calculation.  Can anyone provide me with the ACS table number?  Any help would be greatly appreciated.
Thanks,
Jim Hubbell
Transportation Planner II
Mid-America Regional Council
600 Broadway, Suite 200
Kansas City, MO  64105-1659
816.701.8319 voice
816.421.7758 fax


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