Traffic Barriers on Curves, Curbs, and Slopes

A review of past research and accident databases, conduct of full-scale testing, and computer simulation and validation were conducted in an attempt to develop definitive guidelines for the placement of traffic barriers on curves, curbs, and slopes. Initially, more extensive computer simulation and additional testing was to be conducted in order to develop the definitive guidelines. However, computer simulation and validation efforts were less than successful due to the inability of the computer software to model the complex vehicle/barrier interactions that occur in a full-scale crash test. Due to this problem, it was decided to redirect the remaining contract effort at solving geometric and hardware problems with barriers. Seventeen full-scale tests were conducted on 15 different configurations of barriers on curves, curbs, and slopes. Hardware modifications were developed and tested to improve the performance of a G4(1S} system in combination with a 6-in (152.4-mm) asphalt dike. A Modified Thrie Beam guardrail was used to improve barrier performance on superelevated terrain with a curved guardrail. The following barriers demonstrated acceptable performance: a G4(IS} system with an 1192-ft (363.3-m) radius, a 27-in (685.8-mm) concrete wall with an 8-in (203.2-mm) brush curb, a G4 (IS) system with a 4-in (101.6-mm) Type H curb, and a G4(IS) system installed on a downslope.