Numetric has provided several Social Vulnerability Index filters and metrics to assist in crash and safety analysis for each agency. These filters and metrics can be great data points to assist in considering areas of greater vulnerability within your jurisdiction.
(A sample Network Screening using the Social Vulnerability Index (Overall) to display roadways with an overall SVI below .85 in a given area ranked by ePDO.)
Overview of Social Vulnerability Index
SVI indicates the relative vulnerability of every U.S. Census tract. Census tracts are subdivisions of counties for which the Census collects statistical data. SVI ranks the tracts on four variables: Socioeconomic Status, Household Characteristics, Racial & Ethnic Minority Status, and Housing Type.
For more comprehensive documentation around SVI data, see the Center for Disease Control and Prevention's SVI documentation, found here.
Each of these variables have their own related social factors, as outlined below:
Socioeconomic Status
Below 150% Poverty
Unemployed
Housing Cost Burden
No High School Diploma
No Health Insurance
Household Characteristics
Aged 65 & Older
Aged 17 & Younger
Civilian with a Disability
Single-Parent Households
English Language Proficiency
Racial & Ethnic Minority Status
Hispanic or Latino (of any race); Black and African American, Not Hispanic or Latino; American Indian and Alaska Native, Not Hispanic or Latino; Asian, Not Hispanic or Latino; Native Hawaiian and Other Pacific Islander, Not Hispanic or Latino; Two or More Races, Not Hispanic or Latino; Other Races, Not Hispanic or Latino
Housing Type & Transportation
Multi-Unit Structures
Mobile Homes
Crowding
No Vehicle
Group Quarters
Each census tract then receives a ranking for each of the four factors, as well as an overall ranking summarizing all four factors.
Each Crash is assigned an SVI ranking based on the location of the crash. The SVI ranking is based on the ranking of the census tract or county in which the crash occurred. SVI rankings are displayed as decimal values (.0 - 1). A ranking of 1 indicates the most vulnerable, while a ranking of 0 indicates the least vulnerable.
This ranking represents the proportion of tracts that are greater than or lower than a tract of interest in terms of social vulnerability. For example, an SVI ranking of 0.85 signifies that 85% of tracts in the state or nation are less vulnerable than the tract of interest and that 15% of tracts in the state or nation are more vulnerable.
(A query with the Social Vulnerability Index (Overall) filter set to display crashes with an SVI below .5126, and sidebar metrics displaying the distribution of crashes in the SVI Overall, and Transportation Index and Groups.)
Available SVI Filters/Metrics
Each Social Vulnerability Index (SVI) Variable is available in Numetric as a Filter and a Metric. These filters/metrics can be used to evaluate crashes that occurred in areas of a given social vulnerability index:
SVI - Overall Vulnerability
SVI - Housing Type & Transportation Status
SVI - Socioeconomic Status
SVI - Household Characteristics
SVI - Racial & Ethnic Minority Status
Each of the above filters is also available as a “Group” filter or metric, where the values are grouped into ranges, rather than individual values.
SVI - Overall Vulnerability (Grouped)
SVI - Housing Type & Transportation Status (Grouped)
SVI - Socioeconomic Status (Grouped)
SVI - Household Characteristics (Grouped)
SVI - Racial & Ethnic Minority Status (Grouped)
(The Metrics Sidebar highlighting the difference between the “Group” and “Non-group” SVI metrics.)
The diagram below highlights the variables that are evaluated in each of the different SVI filters and metrics.