Systemic Approach to Safety – A risk-based approach to preventing crashes
The Lane County Transportation Safety Action Plan (TSAP) emphasizes a systemic approach to safety, which uses a risk-based approach to prevent crashes. The systemic approach looks at crash history on an aggregate basis to identify high-risk characteristics. The TSAP evaluated crash data between 2007 and 2014, which showed a total of 24,787 crashes in Lane County. Most fatalities (54%) occurred in rural Lane County (2.4 times higher than the fatality rate in the Eugene-Springfield metro area).
Between 2007 and 2008, 168 people died in rural Lane County (compared to 72 people in the metro area). This is consistent with national trends, which show that crash rates tend to increase with urban densities due to more frequent interactions between vehicles, but crash severity and therefore casualty rates tend to be higher in rural areas due to higher traffic speeds.
Rural crashes are spread out over a wide area. These crashes are rarely identified through the traditional site analysis approach because it is difficult to isolate high-crash locations. The systemic approach provides an alternative method to address these crash types and fulfill a previously unmet need. The system approach answers the question:
Do all systems and crash types present equal opportunities for crash reduction, or do specific parts of the system and certain crash types offer a greater opportunity to save lives?
While there were system distinctions in the urban area (i.e. 47% of fatal and severe-injury collisions were at intersections), there were no obvious correlations within the rural system (e.g. only 18% at intersections) other than the facility type being arterial or collector roads versus local. Additional data analysis is needed to refine the roadway geometry characteristics relative to the crashes, as the aggregate data review indicated no strong correlation between collision frequency and severity at various alignments, such as vertical and horizontal curves. However, the crash type (i.e. roadway departure) stood out as a high risk factor and the most common contributing factor in all fatal collisions was excessive speed.
This data indicates a significant opportunity to save lives by focusing on addressing these high risk factors, which are preventable.