RUCA Data Version History
Version 1.1: First publicly released RUCA files. Based on 1998 ZIP code areas and 1990 Census commuting data. Data are not available.
Version 1.11: ZIP code correction made in Oregon file. Click here for more on Version 1.11.
Version 2.0: Based on 2004 ZIP code areas and 2000 Census commuting data.
An additional 2.0 version based on 2006 ZIP code areas and 2000 commuting data is also available.
Changes from Version 1.11 to Version 2.0
Changes to the RUCA criteria:
- Urban Clusters were used by the Census Bureau to define small-town and large-town cores. In 1990, Urban Clusters were not available and place boundaries were used instead by the Census Bureau. In addition, the Census Bureau drastically changed the method for delineating Urban Areas, resulting in significant changes in the RUCA metropolitan cores (e.g., substantially more Urbanized Areas and subsequently more Metropolitan Areas were designated). These two changes represent the most important differences between 1990 and 2000 RUCAs, and effectively render them non-comparable for purposes of analyzing actual change in rural-urban status during the 1990s.
- In 1990, the Census Bureau allocated tract-of-work where such data were missing, using an unsatisfactory algorithm; in 2000 we applied our own algorithm based on data for flows with similar place and/or country origins and destinations, resulting in an improved set of commuting flows.
- In 1990, many tracts with insufficient population or commuting data were coded ‘99’. In 2000 we have no missing RUCA data; such tracts were coded according to their initial “structure” coding as UA, large UC, small UC, or rural (almost all were rural; 1 or 2 were small UC).
- In 1990, tracts were included as part of an urban core if 20% or more of their population were in the corresponding UA or UC.
- The lower threshold for “low commuting” flows was raised from 5% to 10%.
- For Version 1.11, secondary work commuting flows of 30% or greater and 5-29% were assigned for codes 5,6,8, and 9 with the same modifier digit (.x) as the core city/town (i.e., 4 and 7). For Version 2.0, codes 5,6,8, and 9 were assigned their modifier digit (.x) based on their own commuting patterns.
Changes to the codes:
Added: 4.2, 5.2, 6.1, 10.6.
Changes to the official wording:
For the primary code title, “large town” is replaced with “micropolitan.”
In the descriptions, “large town” and “small town” are replaced with “large UC (Urban Cluster)” and “small UC.”