C5. Crash Location
The exact location on the roadway to document where the first harmful event of the crash occurred.
The optimum definition of Crash Location is a route name and GPS (global positioning system)/GIS (geographic information system) locator, if a highway agency has a linear referencing system that can relate geographic coordinates to specific locations in road inventory, traffic, driver, and other files. The location information in a crash file must have the capability to be linked to location information in these other important files required to study site-specific safety issues. GPS/GIS provides the latitude/longitude coordinates indicating where the crash occurred.
Linear Referencing System (LRS)
An LRS can create complex overlays of multiple events or occurrences along a route to support corridor planning, pavement rehabilitation, or other complex analysis. An LRS permits users to share information maintained by different data providers across different data layers. An LRS is not created by the geographic information system (GIS), but is actually replicated to model what is in the field. All linear data (traffic volumes, pavement types, speed limit zones, etc.) and point data (crashes, signs, etc.) collection efforts need only specify the location or endpoint locations in terms of the LRS components.
Link Node System (not recommended)
Note: States with no system or a link node system should plan to develop or upgrade to a linear referencing system or one that documents latitude/longitude coordinates.
Critical for problem identification, prevention programs, engineering evaluations mapping, and linkage purposes.