Sequential Kinking and Flared Energy-Absorbing End Terminals for Midwest Guardrail System

Document Type

Journal Article

Publication Date


Subject Area

planning - safety/accidents, mode - rail


Sequential kinking terminal, Performance, NCHRP Report 350, Midwest Roadside Safety Facility, Impact tests, Guardrail terminals, Flared terminals, Crash tests, Collision tests


The Midwest guardrail system (MGS), developed at the Midwest Roadside Safety Facility, was designed to improve the performance of traditional strong-post, W-beam guardrail systems. These improvements include decreasing the potential for rollover with high center-of-gravity vehicles, decreasing the potential for rail rupture at the splice locations, and decreasing the sensitivity of the system to the installation rail height. However, safe guardrail termination options for the MGS must be developed before the system can be implemented on the roadside. Two end terminal designs, the sequential kinking terminal (SKT) and the flared energy-absorbing terminal (FLEAT), were partially redesigned and crash tested in conjunction with the MGS according to NCHRP Report 350 criteria. The new versions of the terminals were named the SKT-MGS and the FLEAT-MGS to designate them for use with the MGS. To evaluate the performance of the terminals with the MGS, a series of four full-scale crash tests was conducted: two redirection tests, NCHRP Report 350 Test Designations 3-34 and 3-35, and two head-on impacts, Test Designations 3-30 and 3-31. The results from the four crash tests were found to meet all relevant safety requirements. The SKT-MGS and FLEAT-MGS end terminals are the first successfully tested end terminals for use with the MGS.