SPR 21-603: Incorporating Crash Severity and Continuous improvement of SHIFT

The Strategic Highway Investment Formula for Tomorrow (SHIFT) is KYTC’s data-informed approach for comparing capital improvement projects to help prioritize limited transportation funds. SHIFT 2022 will incorporate more advances in methods and flexibility. This project will help KYTC staff further refine SHIFT and improve the formula’s safety components. The current version of SHIFT uses all crashes to compute excess expected crashes (EECs) for prioritizing projects. All crashes are not equal, and locations with a higher proportion of severe (fatal and injury) crashes currently receive the same weight as locations with an equal number of property damage only crashes. However, the use of only fatal and serious crashes presents a small-statistics problem where variability limits the reliability of future crash estimates. The EPDO technique (computation of an equivalent number of property damage only crashes that uses higher weights for more severe crashes) is not easily integrated into the Empirical Bayes (EB) method used to compute EEC. This project will develop a combined EPDO and EB method for use in SHIFT 2022 OBJECTIVES • Assist the Planning Division with on-call resources such as those availed during the last round of SHIFT. • Better align SHIFT’s safety mode with KYTC’s Strategic Highway Safety Program and its goal of reducing fatalities and serious injury crashes. • Improve safety inputs into SHIFT benefit-cost analysis.