A summary of Urban SDK's Collision Index Data specification.
1.0 Introduction
Collision Index is a metric calculated by Urban SDK that represents the relative risk of severe collisions occurring on a road segment. It is provided as a single yearly value for every public roadway with an index range of 0-1, where a value of 1 indicates that the characteristics of the selected road segment share a strong similarity to roadways that experience severe collisions.
Disclaimer: A high Collision Index value for a roadway does not mean that a severe collision has occurred or will occur. It suggests that the roadway shares significant characteristics with other roadways where severe collisions are common.
2.0 Methodology
Data Collection & Processing
Urban SDK calculates Collision Index with the input of annual historical fatal crashes, collected from the Fatality Analysis Reporting System (FARS) database which is maintained by the National Highway Traffic Safety Administration (NHTSA). This data is combined with annual traffic speed, Average Annual Daily Traffic (AADT) volume, roadway characteristics like functional class, speed category, and road geometry, as well as neighborhood characteristics like road network density, and whether it is in an urban or rural environment.
3.0 Data Specification
Metadata Fields
Metadata fields that are provided for all data are detailed in Urban SDK's Linear Referencing System (LRS) specification.
Data Fields
The following table is the format in which downloaded Traffic Speed data will be provided:
| Field | Type | Description |
|
|
integer | The year associated with the provided data. |
|
|
numeric |
The calculated collision index value for the selected road segment and year. |
Annual Value: Collision Index is a single annual value for every segment of roadway and is not disaggregated by month, day of week, hour, or period.