A Data-Driven Process for Prioritizing Highway Safety Investments in Idaho

摘要

The Idaho Transportation Department (ITD) developed a data-driven method for identifying thehighest priority locations for safety improvements and for evaluating the potential safety benefitsof candidate projects. DKS developed criteria defining the Safety Health Score for each segmentof the state highway system and used the score to identify the highest priority locations for safetyanalysis in each ITD district. Visualization of the highest priority locations was aided byGeographic Information System (GIS) mapping of the Safety Health Score. Five years of crashdata for the high-priority locations was used to identify potential improvement projects. TheHuman Factors Guidelines were used to help identify crash causality and appropriatecountermeasures for consideration. The Highway Safety Manual procedures provided the basicmethodology for estimating the potential reduction in the number and severity of crashes fromeach of the potential improvements. In the application of the corridor safety analysis, a newapproach was used to develop the data needed for the Highway Safety Manual procedures. Theproject team used the digital video logs that are collected for all state highway mileage each yearto prepare estimates of values for numerous roadway characteristics including lane widths,shoulder widths, and locations of driveways and other private access points. The teamdeveloped a method for prioritizing safety projects based on an assessment of potential crash costsavings and the benefit-cost ratio of each potential project.