117. The representative of the United States of America informed AC.3 about phase 2 of the Pedestrian UN GTR. He indicated that his country preferred that the Injury Assessment Reference Values (IARV) remain optional so that Contracting Parties could develop appropriate values for their domestic regulations based on local injury risk curves. He informed the World Forum that his administration had published research on injury risk curves for probability of injury as a function of flexible lower legform (FlexPLI) ligament elongation. He clarified that this publication had been submitted to the IWG and can also be accessed directly from the NHTSA Docket (Docket number: NHTSA-2008-0145-0013). He reported that his administration had also begun development of a costs and benefits analysis that is expected to be completed in late 2015. Concerning the bumper test area, he informed AC.3 that the IWG agreed to accept a proposal tabled by the Federal Highway Research Institute (BASt) of Germany that would limit the minimum test area. The representative of the United States of America invited WP.29 representatives to provide comments on a new proposal on the headform test procedure that was expected to be issued prior to the upcoming June session of WP.29.