Justification and prioritization of projects under the Federal Hazard Elimination Program (HES) are based on the calculation of a Safety Improvement Index (SII). This formula is a benefit-cost ratio, which critically depends on the percentage of expected crash reduction from before-improvement levels. These crash reduction percentages, or factors, have historically come from many sources, which are now dated and questionably applicable. The goal of the study was to validate the crash reduction factors that the Texas Department of Transportation utilizes in SII calculations. The before data represents fatal and serious injury crashes that might have been prevented by the implemented projects. (Author/publisher) For the covering entry of this conference, please see ITRD abstract no. E213531.
Samenvatting