Roadway departures account for over half of all fatal crashes, some of which could have been prevented if a vertical pavement edge drop-off had not been present. Drop-offs occur when there are height differences between a paved road and the adjacent graded material. Conventional paving techniques result in vertical or nearly vertical pavement edges, which can cause safety concerns when they are exposed.
A cutting-edge technology known as the SafetyEdge℠ is a treatment that minimizes drop-off-related crashes. With this treatment, the pavement edge is sloped at an angle of 30 degrees to reduce the resistance of the tire remounting the drop-off. The reduced resistance is intended to allow a more controlled reentry onto the traveled way.
- Development of Crash Modification Factors for the Application of the SafetyEdgeSM Treatment on Two-Lane Rural Roads
- Safety Effects of the SafetyEdge℠: Technical Summary of Crash Modification Factor – [HTML, PDF]. FHWA-SA-17-044 is useful for practitioners and decision-makers. It summarizes the findings of a multi-state analysis with statistically significant CMFs for a number of crash types.
- SafetyEdge℠ Crash Modification Factors Tech Brief. This Iowa State University Tech Brief documents a safety analysis of Iowa use of the SafetyEdge℠ installed during 2010 and 2011.
- Safety Evaluation of the SafetyEdge℠ Treatment – [HTML, PDF]. FHWA-HRT-11-024 examines early findings on the safety effects, costs, and benefits based on limited number of installations and crash data available at the time.
- Safety Evaluation of the SafetyEdge℠ Treatment, Summary Report – [HTML, PDF]. FHWA-HRT-11-025 provides a brief synopsis of the study and findings in Publication FHWA-HRT-11-024.
- State of the Art Report 10: Influence of Roadway Surface Discontinuities on Safety. TRC Number E-C134 is designed to help highway engineers evaluate roadway maintenance guidelines and priorities. The report addresses safety issues related to several roadway features including a chapter on pavement edges which begins on page 38 of 88.
- Safety Impacts of Pavement Edge Drop-offs. This joint FHWA/AAA report quantifies the scope of the pavement edge drop-off problem.
- State of the Art Report 1: Interaction of Vehicles and Pavements. TRR 946 features "Pavement Edges and Vehicle Stability: A Basis for Maintenance Guidelines" study that set the foundation for the development of SafetyEdge℠ technology.
- Pavement Edges And Vehicle Stability – A Basis For Maintenance Guidelines. This Texas study developed a comprehensive treatment for of pavement edge geometry.