|Characteristic||Average Minutes||Standard Error||Sample Size|
|Less than 4-year degree||20.1||3.4||137|
|4-year degree or higher||18.9||1.5||153|
|Household income less than $75K||18.0||1.8||143|
|Household income $75K or more||22.1||4.1||98|
|18 to 54 years old||21.2||2.3||183|
|55 or older||16.5||2.0||109|
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.