Proposal to update references to the three-dimensional “H” point measurement and calibration procedure pursuant to the transposition of these provisions from the Consolidated Resolution on the Construction of Vehicles (RE3) to Mutual Resolution No. 1.

Revised proposal based on document GRSP/2024/7 to update references to the three-dimensional “H” point measurement and calibration procedure pursuant to moving such provisions from the Consolidated Resolution on the Construction of Vehicles (R.E.3) to Mutual Resolution No. 1.

Proposal to update references to the three-dimensional “H” point measurement and calibration procedure pursuant to the transposition of these provisions from the Consolidated Resolution on the Construction of Vehicles (RE3) to Mutual Resolution No. 1.

The provisions of UN Regulation No. 16 (paragraph 6.4.1.4.1.) only allow contact of the chest of the dummy driver with the steering assembly, provided that this contact fulfils certain energy-dissipation test requirements and that contact does not occur at a speed higher than 24 km/h. In response to the updated provisions of UN Regulation No. 16 which allow greater forward displacement of occupants, UN Regulation No. 17 will be updated to provide requirements on improved energy-dissipation criteria for those areas of the rear of seats and head restraints where impact of the head of the rear occupant may occur. Given the update to UN R17, this proposal would amend the scope of UN R25 (which has not been updated with regard to energy dissipation) to cover only vehicle categories M2 < 3.5 tons and N1 and mention explicitly that application to N2 and N3 vehicle categories is optional.

Proposal to clarify that head restraints approved under UN R17 are exempt from the requirements of UN R25 and that UN R25 does not apply to coach and bus seats approved under UN R80.

Correction to include provisions for the exemption of certain headrests of M₂ and M₃ vehicles approved according to UN R80.

UN R17, R25 and R80 address head restraints for various categories of vehicles. In order to prevent redundant application of these regulations, this amendment clarifies that head restraints approved under UN R17 would be exempted from the requirements of UN R25 and that UN R25 does not apply to coach and bus seats approved under UN R80.

Proposal to limit the overlap of this head restraint regulation with UN R17 which also addresses head restraints within the context of seat integrity. The amendment would exempt any vehicle head restraints approved under UN R17 from the requirements of UN R25. Presently, only M1 passenger cars qualify for this derogation.

Report on the project to assess the use of a dynamic geometry test procedure and to validate the calibration of
marker tracking systems so that the dynamic geometry measurements are of equivalent, traceable robustness to conventional load cell or accelerometer measurements.