There is a total vehicle count but it is the total number available at
the household. Doesn't always match the vehicles you get when you
multiply add up all the vehicles used to commute.
Thanks Ed: I didn't want to have to correct Steve.
Isn't there a total
vehicle count also somewhere in ACS? I recall using it to calc the top
category so that it all comes out right.
From: ctpp-news-bounces(a)chrispy.net [mailto:email@example.com]
On Behalf Of Ed Christopher
Sent: Friday, May 20, 2011 6:06 PM
Subject: Re: [CTPP] RE: private vehicle occupancy data from ACS
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.
On Behalf Of Jim Hubbell
Sent: Friday, May 20, 2011 4:35 PM
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.
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