Crash reduction factors (CRF) provide agencies with an estimate of the expected crash reduction and/or benefits associated with various countermeasures. However, since local conditions (e.g., roadway, driver, traffic, weather, crash investigation techniques) may vary from agency to agency, state specific CRFs provide a more accurate indication of the effectiveness of various countermeasures. Prior to the development of the Crash Reduction Analysis System Hub (CRASH), the Florida Department of Transportation (FDOT) did not have a central database that combined crash data and safety project data to determine CRFs, or a mechanism in place to provide FHWA with a report on the effectiveness of safety projects in reducing crashes. The individual districts maintained the historical data for their safety improvement projects, which were in various formats and were not easily accessible for developing CRFs. In an effort to systematically maintain statewide safety improvement project data and facilitate a continual process of developing and updating state specific CRFs, the FDOT funded a research project with the Lehman Center for Transportation Research to develop the CRASH application.
The CRASH application is a web database of safety improvement projects on the FDOT intranet. The District Safety Engineers (DSE) input all Highway Safety Improvement Program (HSIP) funded projects into CRASH, which stores individual safety improvement projects and crash data. The application uses before and after crash counts to evaluate the CRFs for the countermeasures implemented in the safety improvement projects entered in the system. The State Safety Engineer (system administrator) updates the CRFs annually; although they can be updated at any time. The CRFs are typically calculated based on five years of before and after data, but the system administrator may specify a time period for the calculation.
The CRASH application enables the DSEs to easily evaluate different countermeasures and conduct a benefit-cost analysis by inputting project limits and selecting crash data years. CRASH currently includes 135 different improvements types. When the user selects a proposed countermeasure, the application provides a range of CRFs for crashes in various categories based on historical crash reductions or increases associated with past projects. The user can select the standard CRF or input a user defined value in cases where no sufficient studies in Florida exist to develop a state specific CRF.
The CRASH system enables easy performance tracking of safety efforts. It provides various functions for data retrieval and exportation for other analysis and reporting purposes, including the annual HSIP report.
- Developed an online database of safety improvement projects and state-specific CRFs.
- Automated processes for benefit-cost analysis and safety project evaluations.
The CRASH application has enabled Florida to develop state-specific CRFs for several countermeasures based on the evaluation results of implemented HSIP projects. The system has also reduced the level of effort required to conduct benefit-cost analyses and project evaluations by automating the processes.
Transportation Safety Engineer
Florida Department of Transportation