|Personal vehicle||Standard error||Air||Standard error||Bus||Standard error||Train||Standard error||Other||Standard error||Total|
NOTES: Only trips in which the transportation mode could be identified in both travel directions are considered.
The percentages in this table for going trips by return trips of the same mode do not match the percentages in Table 7 for same mode trips in each direction, because the two tables use a different base for figuring percentages. The data in this table are arrayed directionally (going x return), while the percentages in table 7 are based on the total number of trips via each mode in both directions combined.
The difference between shaded cells on the same row are not statistically significant, except for going mode train, the percentages for return mode personal vehicle and bus, and for going mode personal vehicle and return mode other, are statistically different. All other shaded cells on the same row are not statistically different.
Underlined estimates are based on a small sample size (<30) or a coefficient of variation greater than 30% and are not reliable.
SOURCE: U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics, Federal Highway Administration, National Household Travel Survey, long-distance file, 2001 (Washington, DC)