In a recent blog conversation about how to get information on trips besides the trip to work, which is what the Census and American Coummunity Survey (ACS) cover, someone pointed a great data source out to me. It's the 2009 National Household Travel Survey from the U.S. Department of Transportation's Federal Highway Administration. Check out this Summary of Travel Trends (83 page pdf). All of the data below pertain to the U.S. as a whole.
In the Summary's Table 5 we see average annual person miles traveled (PMT) by trip purpose:
Again, the Census and ACS only cover the trip to work, which was responsible for just 19.0% of PMT in 2009 according to the data above. The trip purpose with the most PMT is actually "social/recreational" with 30.3% of PMT.
Table 9 shows the number of trips made by mode of transportation and by trip purpose. For all trip purposes averaged together transit has been basically flat since 1990 (to 2009), walking has increased as the mode from 7.2% to 10.4% of all trips, and "Other", which probably includes bikes, increased from 3.2% to 4.2% of all trips. Interestingly, walking for social and recreational trips increased as the mode from 9.9% of such trips in 1990 to 17.5% of such trips in 2009. I'll leave the "why" on this to others. The state of the economy and gas prices at the various data points probably have some explanatory power, but perhaps shifting preferences do as well.
I've really just scratched the surface of these data here. I hope you take a look at this free information yourself. Your taxes paid for it, so go nerd out on it!