The Hazard Elimination Program (HEP) is the section of the Safety Management System that focuses on road improvements and includes analytical tools for identification of safety problems and their remedies. This research project reviews the results of the past research for Indiana and other states and develops guidelines that present a set of tools for hazard elimination through road improvements. It also includes developing regression models for predicting crash frequencies at all-way and two-way stop-controlled intersections. Negative binomial regression was used to develop separate models for two-way and all-way stop controlled intersections. These models predict typical frequency of all crashes, property damage only crashes, and injury/fatal crashes at unsignalized intersections. In addition, improved criteria have been proposed for screening the Indiana road network for high-crash locations. The proposed criteria incorporate the level of uncertainty present in the process and consider severity of crashes. The primary outcome of the project is the "Guidelines for Highway Safety Improvements in Indiana," which comprises the second volume. Within this volume, the research results are compiled with other components selected after critical analysis of the present state-of-the-art and state-of-the-practice safety management methods. The Guidelines are ready to use by safety engineers and may also serve as a textbook for inexperienced users. The Guidelines include all required equations, tables with required default values, and calculation forms that organize the HEP process. The calculation forms can be used as an interface design for a computerized version. All major computational steps are illustrated with examples and a comprehensive example is included to demonstrate the entire HEP process.
Samenvatting