PARAMETRIC STUDY ON IMPROVEMENT OF G4(1S) STRONG POST GUARDRAIL SYSTEM

The G4(1S) strong post guardrail system is the most common guardrail system in the USA. Full- scale crash testing indicated that the vehicle rolled onto its impact side after exiting the guardrail system. This collision behavior of the roadside structure increases the occupant risk and is considered unsatisfactory for safety. Improvement of the G4(1S) guardrail system becomes an important issue concerned by the FHWA. The subject of this investigation is to understand the system behavior through parametric study and present a feasible approach for structural improvement. This paper provides a roadmap for simulation of highway safety structures. Some of the noteworthy observations are presented and discussed. The approach of reducing the embedment depth of post is investigated through both FE component simulation and full system crash simulation. This approach is recommended and is anticipated to be favorable for minimizing the risk of rollover of vehicles impacting the G4(1S) guardrail system.