Mr. Nguyen explained that NHTSA for the time being is not yet prepared to accept the currently proposed injury threshold values, especially since the injury risk curves are missing. Both, Mr. Takahashi and Mr. Zander offered to show their injury probability assessments which both are representing different approaches. Mr. Martin clarified that of course the performance thresholds of the impactors have to be agreed but that the question of the injury risk curves is a separate information that is needed to derive the injury risk of the threshold values from and to justify respective rulemaking.

In response to this, Mr. Takahashi presented a document that he had already shown in the 2012 SAE World Congress (document GTR9-6-26; the full paper SAE 2012-01-0277 is available for purchase). He explained that a two-step approach was used in this: In a first step the injury probability functions were developed and then these were double-checked against the data of the EEVC LFI for validation purposes. Mr. Takahashi concluded that finally this process showed equivalent injury probabilities for the FlexPLI and the EEVC LFI, that the bending moment threshold well corresponds to the EEVC LFI’s acceleration and that the MCL elongation is slightly more conservative then the knee bending angle of the EEVC LFI.

Mr. Nguyen appreciated the presentation of Mr. Takahashi and mentioned that NHTSA would welcome to also see similar information for the BASt approach, if possible. However, he also stated that for the time being NHTSA would appreciate to allow contracting parties to the GTR Agreement to use the threshold values a bit flexible, especially when seeing the conflict of the US with the Part 581 requirements.

Mr. Broertjes strongly opposed that flexibility or options should be allowed. Requirements should be set so that all contracting parties can use them. Ms. Chaka pointed out that NHTSA may have also difficulties with the headform test where such flexibility is not provided. Mr. Knotz added that such flexibility then must also be provided for other contracting parties, for example China or India or Russia, if they came up with such a request. However, he doubts that this could work. Mr. Damm added that the presentation of Mr. Takahashi had shown the comparability of the requirements of the FlexPLI with those of the EEVC LFI and that NHTSA had agreed to the original GTR No. 9. Mr. Broertjes supported that therefore this should not be an issue.

Mr. Hardy commented that the data shown by Mr. Takahashi referred to the 1998/2002 EEVC report where in fact 15 degrees were used for the bending angle of the EEVC LFI. The 19 degrees referred to in Mr. Takahashi’s presentation were derived later in the work of TRL for the European Commission when doing the feasibility assessment for the phase 1 of the European requirements. In this study of TRL in 2004, new data from Matsui et al. were included. Mr. Takahashi explained that the Matsui paper contained mistakes. Therefore, the data of a study of Dr. Konosu were used that are correct.