Proposal to amend UN GTR No. 24 by modifying test procedures, definitions, and requirements for brake particle emissions measurement. The amendment introduces improvements including revised definitions (vehicle electrification type, material formulation, pad size), updated measurement tolerances and signal filtering requirements, provisions for brake filtering systems, enhanced specifications for drum and electromechanical brake systems, relaxed cooling airflow adjustment requirements, and a new test cycle for speed-limited vehicles. Documentation of calibration requirements and ongoing quality controls are clarified throughout.
Proposal to add para. 8.1.2. to specify required measurements for test vehicles, including use of onboard measurement data as an alternative to measurement devices for engine speed, intake manifold pressure, and fuel flow rate when accuracy and frequency meet minimum requirements, and to add para. 8.1.2.1. to specify measurements specific to TP1 including electrical current and voltage at REESS or inverter inputs and ICE speed, intake manifold pressure, and fuel flow rate.
Proposal to amend para. 3.1.2. of Annex 5 to clarify the verification procedure for SOCR/SOCE monitors by specifying that electric range and UBE values shall be measured at the time of verification with related monitor values collected before and after the verification test procedure, that indicator values collected after the verification test procedure shall not be considered in Part A verification, and that measured SOCR and measured SOCE values shall be determined by dividing measured values for electric range and UBE by certified values for electric range and UBE respectively, expressed in per cent.
Report on the third inter-laboratory study evaluating the repeatability and reproducibility of particulate emission factors using GTR 24 (1st amendment) across 14 laboratories worldwide. The study assessed laboratory proficiency in brake particulate matter and particle number emissions measurements for light-duty vehicles, testing two low-metallic brakes and one low-emitting NAO brake using the WLTP-Brake cycle. Inter-lab coefficient of variation for PM₁₀ was 10-15% for low-metallic brakes (4.5-8.5 mg/km emission levels) and 30% for the NAO brake (1.5 mg/km). Intra-lab repeatability for PM₁₀ was less than 5% for low-metallic brakes but higher for the NAO brake. A success rate of 94.8% was achieved after applying quality checks, confirming GTR 24 suitability for regulatory testing. The report provides recommendations for GTR 24 amendments including friction work calculation methodology, torque quality metrics, sampling probe setup standardization, and residual torque limits.
Proposal to amend para. 1.1.3. of Annex C1 to clarify that the method for customer values shall be determined in agreement with the authorities only in the case that the specified methods are not applied, and amend paras. 2.1.2. and 3.1.2. of Annex C1 Appendix 2 to correct the technical error in the determination of UBEcertified by specifying that UBEcertified shall be rounded to the nearest whole number if the unit is Wh or to three significant numbers if the unit is kWh, and when the interpolation method is applied, UBEcertified shall be determined by selecting the maximum amongst vehicle H and vehicle L, and if applicable, vehicle M.
Final status report on development of a new UN Global Technical Regulation addressing particle matter (PM) and particle number (PN) emissions from heavy-duty vehicle brake systems. The GTR introduces brake emissions groups based on design and performance characteristics, establishes test parameters for disc and drum brakes across five diameter groups, defines the World Harmonized Heavy-Duty Brake Cycle (WHBC) comprising 246 brake events over 5:39 hours, specifies brake dynamometer hardware requirements with enclosure dimensions of 1950 mm length, 1000 mm height, and 700 mm depth, requires PM10 and PM2.5 gravimetric measurement and particle number counting, and prescribes a friction braking share coefficient (c-factor) of 1 pending availability of additional data. A preliminary interlaboratory study confirms test cycle reproducibility and particle measurement repeatability, with recommendations to specify fixed enclosure and duct dimensions for improved cross-laboratory consistency.
Overview of documents and working party activities for the 95th session of the Working Party on Pollution and Energy (GRPE). Documents address improvements to UN R179 (Laboratory Measurement of Brake Emissions for Light Duty Vehicles) including handling of vehicles with limited speed, brake replacement parts regulation, and GTR 24 (Measurement procedures for Brake corner emission factors). Related documents also cover a new regulation for heavy-duty brake emissions and a new global technical regulation for heavy-duty brakes. Working documents ECE/TRANS/WP.29/GRPE/2026/29, ECE/TRANS/WP.29/GRPE/2026/30, ECE/TRANS/WP.29/GRPE/2026/31, ECE/TRANS/WP.29/GRPE/2026/32, and ECE/TRANS/WP.29/GRPE/2026/53 are submitted.
Proposal to amend UN GTR No. 25 by modifying requirements for State-of-Certified Energy (SOCE) monitors, battery performance requirements, in-use verification procedures for Parts A, B, and C, and related test procedures and annexes. The GTR establishes harmonised methods to determine in-vehicle battery durability performance of Heavy-Duty Pure Electric Vehicles (HD-PEVs) and Heavy-Duty Off-Vehicle Charging Hybrid Electric Vehicles (HD-OVC-HEVs) of categories 1-2 and 2 exceeding 3,855 kg technically permissible maximum laden mass. The document includes tracked changes to Amendment 1 (WP.29/2026/209), with sections subject to discussion or decision indicated in square brackets and strikethrough text denoting proposed deletions.