Primary RUCA Codes, 2010

1 Metropolitan area core: primary flow within an urbanized area (UA)

2 Metropolitan area high commuting: primary flow 30% or more to a UA

3 Metropolitan area low commuting: primary flow 10% to 30% to a UA

4 Micropolitan area core: primary flow within an Urban Cluster of 10,000 to 49,999 (large UC)

5 Micropolitan high commuting: primary flow 30% or more to a large UC

6 Micropolitan low commuting: primary flow 10% to 30% to a large UC

7 Small town core: primary flow within an Urban Cluster of 2,500 to 9,999 (small UC)

8 Small town high commuting: primary flow 30% or more to a small UC

9 Small town low commuting: primary flow 10% to 30% to a small UC

10 Rural areas: primary flow to a tract outside a UA or UC

99 Not coded: Census tract has zero population and no rural-urban identifier information

Secondary RUCA Codes, 2010

1 Metropolitan area core: primary flow within an urbanized area (UA)

1

No additional code

1.1

Secondary flow 30% to 50% to a larger UA

2 Metropolitan area high commuting: primary flow 30% or more to a UA

2

No additional code

2.1

Secondary flow 30% to 50% to a larger UA

3 Metropolitan area low commuting: primary flow 10% to 30% to a UA

3

No additional code

4 Micropolitan area core: primary flow within an Urban Cluster of 10,000 to 49,999 (large UC)

4

No additional code

4.1

Secondary flow 30% to 50% to a UA

5 Micropolitan high commuting: primary flow 30% or more to a large UC

5

No additional code

5.1

Secondary flow 30% to 50% to a UA

6 Micropolitan low commuting: primary flow 10% to 30% to a large UC

6

No additional code

7 Small town core: primary flow within an Urban Cluster of 2,500 to 9,999 (small UC)

7

No additional code

7.1

Secondary flow 30% to 50% to a UA

7.2

Secondary flow 30% to 50% to a large UC

8 Small town high commuting: primary flow 30% or more to a small UC

8

No additional code

8.1

Secondary flow 30% to 50% to a UA

8.2

Secondary flow 30% to 50% to a large UC

9 Small town low commuting: primary flow 10% to 30% to a small UC

9

No additional code

10 Rural areas: primary flow to a tract outside a UA or UC

10

No additional code

10.1

Secondary flow 30% to 50% to a UA

10.2

Secondary flow 30% to 50% to a large UC

10.3

Secondary flow 30% to 50% to a small UC

99 Not coded: Census tract has zero population and no rural-urban identifier information

Population data for census tracts, by urban-rural components, 2010:

U.S. Census Bureau, Census of Population and Housing, 2010. Summary File 1, FTP download: https://www.census.gov/census2000/sumfile1.html

Assignment of census tracts to specific urban areas or to rural status was completed using ESRI's ArcMap software and Census Bureau shape files:

U.S. Census Bureau. Tiger/Line Shapefiles, Census Tracts and Urban Areas, 2010: https://www.census.gov/programs-surveys/geography.html

Census tract commuting flows, 2006-2010:

U.S. Census Bureau, American Community Survey 2006-2010 Five-year estimates. Special Tabulation: Census Transportation Planning Products, Part 3, Worker Home-to-Work Flow Tables. https://www.fhwa.dot.gov/planning/census_issues/ctpp/data_products/2006-2010_table_list/sheet04.cfm

Tract-to-tract commuting flow files were constructed from ACS data as part of a special tabulation for the Department of Transportation—the Census Transportation Planning Package. To derive estimates for small geographic units such as census tracts, information collected annually from over 3.5 million housing units was combined across 5 years (2006-2010). As with all survey data, ACS estimates are not exact because they are based on a sample. In general, the smaller the estimate, the larger the degree of uncertainty associated with it.