When things become easier is there a change in behavior?
Looking for inflection points relating to U.S. travel.  Measured in
average miles traveled per person per year in the U.S.
Specifically, did Ford's Model T enable Americans to travel more?

Jamesh --

The answer to this question shows a much more dramatic impact on
travel than I'd imagined: first by the car and later by the airplane. 
It shows people traveling 100x more today than in 1900 -- though we
haven't calculated horse-miles or walking miles.

---

There are 3 databases that help answer this question:
1.  Bureau of Transportation Statistics, which has detailed statistics
on passenger-miles for plane, trains, cars, trucks, transit and even
ferry boats from 1960 to 2001:
http://www.bts.gov/publications/national_transportation_statistics/2003/html/table_01_37.html

2.  U.S. population statistics, from the Bureau of the Census (see
pages 7,8) and the Statistical Abstract published annually:
http://www.census.gov/prod/2001pubs/statab/sec01.pdf

3.  The final piece -- transportation numbers for earlier than 1960 --
is in the Bicentennial Edition of "Historical Statistics of the United
States, Colonial Times to 1970," published by the Bureau of the Census
in 1975.  It's apparently NOT available online, though any
well-resourced public library has a copy of it.

In order to make these numbers digestable, I've put a summary of them
in a spreadsheet, with the numbers for every 10 years from 1900 to
2000.  This way you can run your own calculations, over and above my
summary numbers.  You can find the spreadsheet here -- and your
browser should be able to view the Excel file even if you don't have
the Microsoft spreadsheet:
http://www.mooneyevents.com/travel.xls


A couple of notes on the data:
*  we've used total travel for all trucks and cars (and motorcycles,
when they're added)
*  average mileage on passenger vehicles went down about 20% during
World War II but was pretty steady from 1945 to 1970, with about 9,800
miles per year being put on the average car.
* early Census numbers are in "vehicle miles" and later numbers in
"passenger-miles" -- because there's an average of more than one
person per vehicle the numbers after 1960 are  higher in the Bureau of
Transportation Statistics numbers.
* in 1980 and onward, I've aggregated light rail and heavy rail
commuter numbers for "Transit"

Should there be any problem viewing the spreadsheet, please let me
know via a Clarification Request and we'll repost the numbers in text
format here.

Best regards,

Omnivorous-GA

It is fairly easy to draw a graph of average miles traveled by the USA
population and note various events that may have caused the increases
which have occured the last two centuries, nearly every year.
Determining the order of importance and putting numbers on the events
however is mostly guess work. My guess is American railroads, doubled
average travel miles. and the model T Ford jumped it about 5%  Neil