The objective of this study was to report the results of the continued monitoring of the performance of the modified turned-down guardrail end treatment (Type 7) in traffic accidents. Data for a total of 67 accidents involving the modified turned-down guardrail end treatment were identified. Performance was classified as proper in 51 of the 61 accidents (84 percent) in which it was determined. In the majority of the accidents in which proper performance occurred, the vehicle either traveled onto the top at the guardrail beyond the breakaway section or broke through the breakaway posts and proceeded behind the guardrail.
The performance of this 'weakened turned-down' end treatment has shown that continued use is warranted. Although lull scale crash tests have not been conducted for this end treatment, its performance in the field in actual accidents warrants further use. The rollover problem experienced with the original 'stiff' turned-down design has been substantially reduced. The remaining question concerning the rollover problem relates to the small car. When roadway geometries do not permit the guardrail end to be properly buried in a cut slope and conditions for the use of the BCT cannot be met, the Type 7 end treatment provides a practical alternative.
Digital Object Identifier
Agent, Kenneth R. and Pigman, Jerry G., "Performance of a Modified Turned-Down Guardrail End Treatment in Traffic Accidents" (1992). Kentucky Transportation Center Research Report. 460.