Y-category vehicles are equipped with an Automated Driving System and not designed to carry occupants. They may develop aggressive front structures that could harm passenger cars in accidents. The proposal introduces the Occupant Load Criterium (OLC), derived from velocity-time graphs in crash tests, as a compatibility assessment criterion. OLC multiplied by vehicle mass indicates impact aggressivity. Data from ODB tests show OLC values range from approximately 22 to 35 g across various vehicles. The proposal suggests using a maximum OLC × mass value to prevent excessively aggressive vehicle front structures while keeping current passenger car designs unaffected.

A decision was taken in mid-2025 to start drafting a new regulation collecting relevant safety requirements for Category Y vehicles. UN R127 on pedestrian safety performance could be directly amended to include Y-category vehicles instead of including requirements in a new regulation. TF AVRS agreed to amend UN R127 to include Y-category vehicles. A draft regulation (v4) is available proposing supplement 5 to the 04 series of amendments, including amendment suggestions in scope to determine exemptions for Y-category vehicles based on front structural geometry dimensions rather than R-point criteria.

Proposal to insert a new paragraph 0 introducing supplements 4 and 5 to the 04 series of amendments extending the Regulation to vehicles of categories X and Y, amend paragraph 1 to establish scope and exemptions for categories X and Y, amend paragraphs 2.8, 2.22, 2.29, 2.32, 2.44, and 2.45 to define test procedures and reference areas for vehicles without drivers or manual controls, and amend paragraph 5.3.1.2 to clarify automatic return of ARHSS when vehicle speed exceeds 25 km/h or while an ADS feature is active.

Proposal to establish uniform provisions concerning approval of vehicles of category N₁Y regarding fuel system integrity protection, electrical shock protection, and vehicle crash compatibility in frontal, rear-end, and lateral collisions, modify frontal impact test procedures to reference either UN R94 or UN R137 at manufacturer choice in agreement with the Technical Service, add Crash Compatibility Criterion and Crash Compatibility Value definitions and requirements not exceeding 40 g and 100 g × tonne respectively, modify lateral impact test provisions to reference UN R95 without specific side pole impact applicability, modify rear-end impact test procedures to reference UN R153, add post-crash hydrogen fuel system integrity assessment procedures, add provisions allowing vehicles derived from compliant category X vehicles to be deemed compliant, add electrolyte leakage and REESS retention requirements for electric powertrains, permit vehicles with maximum design speed not exceeding impact speed to be tested at their maximum design speed with compliance to post-impact requirements, and establish extension procedures for vehicles derived from previously approved types.

Field data shows reduction in risk for both males and females, though risk difference between males and females remains with higher risk for females regarding soft tissue neck injuries. Purely geometry-based assessment may not be sufficient; minimizing relative spine movements, forward rebound, evenness and energy absorption are important for equitable protection against whiplash. Discussion concluded that headrests often remain in highest position and do not protect occupants of lower stature optimally, which should not be considered misuse. A forgiving design of backrest and headrest should be targeted. Important to avoid suboptimization and assess more than one single point.

Whiplash injury causes neck pain, stiffness, headache, shoulder pain, and neurological symptoms, with women more sensitive than men. Symptoms occur consistently across rear, frontal, and lateral impacts. Research focuses on nerve injury in spinal ganglia as the injury site, as this explains why long term whiplash symptoms include neurological symptoms independent of crash direction. The Neck Injury Criterion (NIC) measures injury using the formula NIC = 0.2Δa + Δv², where Δa is acceleration difference and Δv is velocity difference. Whiplash motion causes rapid volume changes inside the vertebral canal, with epidural blood volume pumped to compensate. Animal experiments using pressure sensors show pressure changes in skull and spine at different vertebral levels during whiplash events.

Simulation of UN R17 whiplash protection component tests and rear impact sled tests using finite element models of a Toyota Auris seat showed the UN R17 test protocol is not robust. A modified seat model approved in component tests (displacement, strength, energy dissipation) but failed the dynamic performance test. Component tests allow large variation in seat properties and do not ensure approval of the dynamic performance test. Seat properties with large effects on whiplash protection in dynamic performance tests can vary substantially with minimal effects in component tests.

Document discusses virtual testing research on rear impact occupant protection. CIDAS data from 132 rear-end collision cases involving 287 occupants shows female occupants comprise 34.15% of rear-impact cases, significantly higher than 21.25% across all accident types. Female passengers predominantly occupy rear seats at 46.95%. C-NCAP 2027 introduces whiplash virtual testing using EvaRID dummy for second-row seats alongside BioRID II for driver seats, with EvaRID injury limits 20% lower than BioRID II. Research includes dummy positioning adjustments and repeatability studies using ISO/TS 18571 evaluation methods.

EuroNCAP conducted whiplash tests using EVARID, a prototype dummy representing a 50%ile female based on BioRID II, on 2024 and 2025 seats with mid and high severity pulses. EVARID showed earlier head restraint contact time but shorter duration, higher NIC values in several cases, higher neck forces Fx and Fz, and higher pelvis and lumbar accelerations compared to BioRID II, indicating different dummy behavior. Next steps include repeatability and reproducibility testing, additional seat testing, evaluation of assessment criteria, and dummy certification.

A finite element model of the average female crash test dummy SET 50F v0.2 for low severity rear impact safety was developed through further tuning and evaluation of the FE SET 1.0.0 model to the FE SET 50F 2.0.0 model. Development included re-meshing of foam, fine tuning weights of body parts, drop tests on abdomen and torso foam, and static spine bending tests of thoracic-lumbar and cervical regions. The FE SET 50F 2.0.0 open-source model is available on the OpenVT platform.

IIHS is implementing virtual testing for whiplash prevention in rear-impact evaluation. A draft test protocol allowing ATD simulation submission was published in June 2025, with rating guidelines and auditing procedures following in December 2025. The evaluation uses metrics including head contact time, maximum NKM, upper neck tension, T1 x acceleration, and pelvis displacement at both 16 km/h and 24 km/h crash pulses. Small SUV ratings began in January 2026. Whiplash prevention with simulation option will be included in IIHS Top Safety Pick awards by February 2028. Future development includes human body model workflows and validation procedures.

The University of Virginia Center for Applied Biomechanics conducted a parametric modeling study of seat performance in rear impact for the Insurance Institute for Highway Safety using OpenVT seat geometry, foam, and structure characteristics spanning real seats. Simulations compared BioRID and EvaRID dummy responses across multiple crash pulses. Some kinematic measures correlated between dummies, while most kinetic measures did not. EvaRID showed greater sensitivity to seatback foam stiffness and pre-crash braking effects than BioRID, with pre-pretensioner reducing several outcome measures.

The Equitable Occupant Protection Task Force 4 met to discuss frontal impact and restraints requirements. An initial prioritization table was tabled in November 2025 and discussed in January 2026, with experts indicating low, medium, or high priority for topics including submarining, abdominal injuries, crash speeds, and seat positions. A proposed updated prioritization table was presented to consider the whole picture when defining future requirements. Current frontal crash performance requirements are mainly defined in UN R94 and UN R137, with specific seatbelt requirements in UN R14 and UN R16. An in-person workshop is scheduled for Tokyo, November 4–6, 2026, to assess robustness and close equity issues. The next meeting is September 7, 2026.

Task Force EDO held an intermediate online Teams meeting on 18 June 2026. The agenda was adopted without amendments. Two informal documents had been submitted to the seventy-ninth session of GRSP. Authorization to amend GTR Nos. 1 and 14 would be submitted to November session of WP.29. Amendments to UN Regulation No. 11, UN Regulation No. 21 and GTR No. 1 would remain part of Phase 1, for consideration at December session of GRSP. The Task Force reviewed proposals concerning UN Regulation No. 100 and intuitiveness, concluding further discussion was necessary. Authorization request to amend GTRs would be submitted to November session of WP.29 by Germany and Republic of Korea. Next meeting: 1-3 September in Paris.

The agenda for the 15th session of Task Force Virtual Crash Testing includes a review of the progress dashboard, summary of feedback from HBM developers based on the survey, continuation of discussion on assessment of readiness of the HBM in 3, 5, 10, and 10+ years, discussion on possible workshop before IRCOBI conference in September, and next steps and next meeting.

Proposal to establish uniform provisions concerning approval of M₁ and N₁ vehicles to assist in prevention of child occupants left inside, specify that vehicles of category M₁ with rear row designated seating positions that can accommodate a Child Restraint System and vehicles of category N₁ with more than one seating row, a Gross Vehicle Mass not exceeding 3,500 kg, and a rear row designated seating position that can accommodate a Child Restraint System shall be equipped with an in-direct plus or direct sensing system, require the system to detect Children Left in Vehicle events for all rear designated seating positions that can accommodate a Child Restraint System with default setting on, allow temporary or long-term deactivation under specified conditions with automatic reinstatement, require warnings to be given immediately after all doors are closed and locked with no more than fifteen to thirty seconds permissible delay and lasting at least ten seconds repeating every ninety seconds for total duration of no less than twenty minutes unless cancelled, establish test procedures including CLIV surrogates aged zero, three, and six years respectively, and specify conformity of production and modification procedures.

UTAC, Linas-Montlhry will host the CLIV IWG meeting 8–11 September 2026. The meeting room, Hellé Nice, is 4080 m², renovated in 2021, accessible without elevator, multimedia equipped, and near the main entrance. Accommodation options include Ibis Montlhry Paris Sud, B&B Hotel Brétigny-sur-Orge, and Comfort Hôtel Linas Montlhry; UTAC can arrange morning and afternoon transport. On-site catering includes water, coffee, tea, and paid lunch through the cafeteria at 15–20 per person. Wi-Fi and French Type E electrical outlets will be available. Delegates should confirm participant numbers by the first week of September using the attendance details form.

UTAC is an automotive test and development center located in Linas-Montlhry, approximately 30 minutes from Paris Orly Airport. The organization operates multiple proving grounds globally, including facilities in Mortefontaine, Millbrook, Finland, and Oued Zem, with over 70 kilometers of test tracks across locations. UTAC provides event and training spaces, including a main modular venue called Le 1924 and a VIP Motul meeting room, alongside specialized testing capabilities for autonomous vehicles, connected vehicles, and electric vehicle development.

Proposal to amend para. 2.27. to define ISOFIX position as a position satisfying requirements of UN R145 to allow installation of ISOFIX child restraint systems as defined in UN R44 and UN R129, amend para. 2.36. to define i-Size seating position as a seating position satisfying requirements of UN R145 to allow installation of i-Size child restraint systems as defined in UN R129, insert new para. 2.48. defining minimum effective seat belt length, insert new para. 5.1.11. specifying minimum seat belt lengths for M₂ and M₃ vehicles, amend para. 5.2.1. to establish requirements for seating positions of M₁, M₂, M₃ and N₁ vehicles suitable for various child restraint systems and require M₁ vehicles to provide child restraint system installation information, amend para. 5.2.2. to remove reference to manufacturer recommendation, insert new para. 11.3. establishing transitional provisions applicable from the official entry into force date and from 1 September 2030, and insert new Annex 8 specifying measurement methodology for minimum effective seat belt length.

Proposal to amend para. 2.27. to define ISOFIX position as a position satisfying UN R145 requirements to allow installation of ISOFIX child restraint systems as defined in UN R44 and UN R129, amend para. 2.36. to define i-Size seating position as satisfying UN R145 requirements for i-Size child restraint systems, insert new para. 2.48. defining minimum effective seat belt length, insert new para. 5.1.11. establishing minimum belt length measurement for vehicles of categories M₂ and M₃, amend para. 5.2.1. to clarify seating position requirements by vehicle category and child restraint system type, amend para. 5.2.2. to remove reference to manufacturer recommendations, amend para. 5.3.5. to limit ISOFIX position requirements to M₁ vehicles, insert new para. 11.3. establishing transitional provisions with entry into force date and 1 September 2030 deadline, and amend Annex 6 Appendix 1 and delete Annex 6 Appendix 2 para. 1.2.