|Characteristic||Estimates (percent)||Standard Error (percent)||Sample Size|
|Less than 4-year degree||30.0||5.0||36|
|4-year degree or higher||28.0||4.1||42|
|Household income less than $75K||31.3||4.6||41|
|Household income $75K or more||23.6||5.3||21|
|18 to 54 years old||28.3||4.1||44|
|55 or older||29.2||4.6||34|
NOTE: All estimates are weighted to represent U.S. noninstitutionalized adult population (18 and older).
SOURCE: U.S. Department of Transportation, Bureau of Transportation Statistics, Omnibus Household Survey, December 2004.