Yes, carpooling went down drastically from 1980-90 and obviously not as
dramatic from 1990-2000. We had over 23% JTW trips by carpool in 1980
Nationwide! 1990 it was down to just over 13% (Nationwide).
I would argue that given the economic condition in 1990 (beaten down)
vs. 2000 (just when the .com bubble was to burst but still upbeat) -
losses in carpooling and transit are not as significant.
Comparing 1995 NPTS and Census 2000 I have the following to offer:
* Trip chaining (the part that goes with JTW) is up during 1990s
(NPTS)
* Huge buy-in in favor of 'flex schedules' during 1990s has
essentially marginalized the significance of JTW (there was a drop of
more than 5% from 1990 to 1995 in peak hour trip starts in our case)
* Each trip taken by transit would have a front end and a back
end trip - (park & ride or ride & walk) - Census asks for only one mode
that covered most of the distance (is comparable to 1990) thereby
undercounting all other trips;
* Vehicle occupancy rate for HBW is a little bit different from
what JTW indicates for the same reason as above - our HBW VOR is less
than what census shows (Tulsa)
Another factor - I have noticed with NPTS is - Women as a percent of
peak hour commuting public is higher than for men (13.6% men vs. 19.7%
women in 1995 for Tulsa). It could be because women tend to keep more
regular hours than men. May be 'Rideshare' programs should focus on
Women-only carpools as a potential market share.
Whatever it may be, we might notice with CTPP an increase in share of
women in commuting during peak hours - to somewhat contributing to the
erosion in transit patronage, decline in carpooling and increase in
commute times.
Viplav Putta
INCOG