Ascertained for persons 14 years of age and over who reported working during the reference week, including Armed Forces personnel, Respondents were asked that principal mode of travel or type of conveyance used to get to their place of work on the last day they worked.

In 1960, the categories were private auto or car pool, railroad, subway or elevated (the latter two categories were combined in tabulations); bus or streetcar: taxicab. other means (taxicab was included in other means in tabulations); walked only; worked at home.

In 1970, the categories are driver, private auto; passenger, private auto; bus or streetcar; subway or elevated ; railroad; taxicab, walked only; worked at home; other means.