Data Dictionary: ACS 2006 -- 2008 (3-Year Estimates)
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Data Source: U.S. Census Bureau
Universe: Universe: Workers 16 years and over in households
Variable Details
B99085. Imputation Of Vehicles Available For Workers
Universe: Universe: Workers 16 years and over in households
Aggregation method:
Addition
Relevant Documentation:
Excerpt from: Social Explorer; U.S. Census Bureau; American Community Survey 2006-2008 Summary File: Technical Documentation.
 
Imputation Rates
Missing data for a particular question or item is called item nonresponse. It occurs when a respondent fails to provide an answer to a required item. The ACS also considers invalid answers as item nonresponse. The Census Bureau uses imputation methods that either use rules to determine acceptable answers or use answers from similar housing units or people who provided the item information. One type of imputation, allocation, involves using statistical procedures, such as within-household or nearest neighbor matrices populated by donors, to impute for missing values.
Overall Person Characteristic Imputation Rate
This rate is calculated by adding together the weighted number of allocated items across a set of person characteristics, and dividing by the total weighted number of responses across the same set of characteristics.
Overall Housing Characteristic Imputation Rate
This rate is calculated by adding together the weighted number of allocated items across a set of household and housing unit characteristics, and dividing by the total weighted number of responses across the same set of characteristics. These rates give an overall picture of the rate of item nonresponse for a geographic area.

Aggregate Number of Vehicles (Car, Truck, or Van) Used in Commuting
The aggregate number of vehicles used in commuting is derived by counting each person who drove alone as occupying one vehicle, each person who reported being in a two-person carpool as occupying one-half of a vehicle, each person who reported being in a three-person carpool as occupying one-third of a vehicle, and so on, then summing all the vehicles. This aggregate is used in the calculation for "workers per car, truck, or van."
Question/Concept History
Beginning in 1999, the American Community Survey questions differ from the 1996-1998 questions only in the format of the skip instructions.
Excerpt from: Social Explorer; U.S. Census Bureau; American Community Survey 2006-2008 Summary File: Technical Documentation.
 
Workers per Car, Truck, or Van
Workers per car, truck, or van is a ratio obtained by dividing the aggregate number of workers who reported using a car, truck, or van to get to work by the number of such vehicles that they used. Workers per car, truck, or van are rounded to the nearest hundredth. This measure also may be known as "Workers per private vehicle."