Corrections to documents submitted by TF-AVRS and approved by GRBP amend terminology in UN R51.03 to harmonize bidirectional spelling, correct vehicle category references in UN R51.03 and UN R165 to reference category X only rather than non-existent category M1Y or category M, clarify in UN R64 that logical signals shall be transmitted to the ADS when an ADS feature is active, introduce references to specific ADS provisions in Annexes 5 and 7 of UN R138.02 and UN R165, add grammatical corrections to UN R141, and align UN R165 terminology with ADS regulation language.

Results of the review of proposals for UN Regulations R28, R51, R64, R138, R141, R142, and R165 regarding autonomous vehicle readiness. Key findings include: inconsistent Mass in Running Order definitions between R51 and R138 versus RE3; unclear special testing provisions in R64, R138, and R165; need for clarification on ADS optical and logical signal transition in R64; redundant full definitions from RE3 in multiple proposals should reference RE3 via footnote instead; inconsistent ADS activity terminology across R64, R141, and R165 should be standardized; incorrect Category Y references in R51 Table 2; and definition and spelling errors in R51, R138, R141, and R165.

Proposal to add Annex 5 Special provisions for the testing of vehicles equipped with an Automated Driving System (ADS) to UN R138. The proposal amends paragraphs 2.7 and 2.8, inserts new paragraphs 2.13 to 2.16 defining ADS, Dynamic Driving Task, bi-directional vehicles, and forward direction, renumbers former paragraph 2.13 to 2.17, amends paragraph 6.2.5 regarding available AVAS sounds, amends Annex 1 item 1.2.2, amends Annex 3 paragraph 3.3.1 regarding testing conditions for bi-directional vehicles, and adds the new Annex 5 explaining how to adapt UN R138 to vehicles equipped with an ADS.

The subgroup on UN R51 and UN R138 met on 14 January 2026 to review comments on outcome documents. Switzerland’s sentence in 3.5. was retained for clarification. JASIC’s definition of EES footnote was changed to reference GRB-68-03. Transitional provisions remained unchanged with a new item added for Annex 1, Appendix 1. Agreement was reached on 6 dB allowance in Annex 7 paragraph 3.4. and 3 dB for three specific cases. A draft paragraph for GRB-68-03 justification will be submitted by email. Switzerland’s proposal SG-13-05-2025-07-30 will serve as basis. GRBP-82-39 includes examples for active systems generating EES and creation of part B for electric vehicles. Work on RD-

The IWG RD-ASEP Subgroup on UN R138 and UN R51 held 13 meetings between October 2024 and September 2025 to amend both regulations regarding sound emissions of electric vehicles. On UN R51, the group agreed to introduce electric vehicles into Annex 7 (ASEP) scope and to add optional sounds and SPL limit lines for M₁ and N₁ vehicles based on vehicle speed, using OICA proposal GRBP/2025/29 as basis. On UN R138, the group aimed to clarify existing text, remove grey zones, and ensure adequate safety levels while limiting environmental impact through maximum SPLs. Working documents are planned for submission to GRBP in February 2026.

IWG RD-ASEP status report to GRBP-82 in September 2025 after the 8th session. RD-ASEP for UN R51 work packages completed with 507 vehicle files delivered in April 2025. IWG recommends no monitoring requirements approval without corresponding collection, analysis, and reporting mechanisms in place. Financing of WP3 required from additional contracting parties or reduced scope planned. RD-ASEP for UN R41 activity closed with GRBP adoption of proposals based on ECE/TRANS/WP.29/GRBP/2025/4, ECE/TRANS/WP.29/GRBP/2025/6, and ECE/TRANS/WP.29/GRBP/2025/7 as amended.

Proposal to replace ECE/TRANS/WP.29/GRBP/2025/2, add a new Annex 5 Special provisions for the testing of vehicles equipped with an ADS, amend paragraphs 2.7. and 2.8. to modify the definition of “Mass in running order” and “Pause function”, insert new paragraphs 2.13. to 2.17. to define Automated Driving System, Dynamic Driving Task, bi-directional vehicle, and forward direction, renumber former paragraph 2.13. to 2.18., amend paragraph 6.2.5. to replace “Driver selectable” with “Available” and modify provisions for AVAS sounds, amend Annex 1 item 1.2.2. and Annex 3 paragraph 3.3.1. to address bi-directional vehicles and reverse modes, and insert provisions in Annex 5 for testing vehicles equipped with an ADS.

Proposal from the GRBP task force on Automated Vehicles Regulation Screening to enable application of UN R138 to ADS vehicles.

Proposal to clarify that the maximum sound pressure requirement at the front plane at standstill condition in reverse shall be equal to the maximum level requirement in motion (defined by the QRTV task force as 75 dB(A) for both standstill and reverse driving).

German-language report on “Noise-optimized AVAS and alternative Vehicle detection systems”, including English-language summary of findings.

“Acceptance of current Pedestrian warning systems (AVAS) in Swiss Population” report including a summary in English.

Proposal for amendments to enable the application of UN R138 to ADS vehicles.

Decision to allow 50km/h urban roads vs 30km/h roads.

“Assessment framework 30 km/h” report in Dutch.

Gives the background to proposal for the Application of Noise Limits to EVs fitted with Exterior Sound Enhancement Systems (ESES) to UN R51

Presentation to support ECE/TRANS/WP.29/GRBP/2024/20

Proposal to clarify the original intent of the Task Force on Quiet Road Transport Vehicles (TF QRTV) conclusion

EC resulting position to
• limit the emission of AVAS to what is strictly necessary for safety
• corollary: prohibit unnecessary noise

Proposal to delete this footnote 2 from the regulation

This proposal aims at aligning the emission of AVAS sounds with safety needs

Proposal to clarify that the maximum sound pressure requirement at the front plane at standstill condition in reverse shall be equal to the maximum level requirement in motion (defined by the QRTV task force as 75 dB(A) for both standstill and reverse driving).

Modifications to adapt UN R138 for application to automated vehicles (based on text of the 02 series proposal to specify the working principles of an Acoustic Vehicle Alerting System (AVAS) and to reduce measurement uncertainties during the measurement of the one third octave bands).

Proposal to specify the working principles of an Acoustic Vehicle Alerting System (AVAS) and to reduce measurement uncertainties during the measurement of the one third octave bands.

Updated proposal for a 02 series of amendments to specify the working principles of an Acoustic Vehicle Alerting System (AVAS) and to reduce measurement uncertainties during the measurement of the one third octave bands.

Proposal to specify the working principles of an Acoustic Vehicle Alerting System (AVAS) and to reduce measurement uncertainties during the measurement of the one third octave bands.

Comments concerning:

• AVAS Pause Switch
• AVAS Sound Pressure Levels
• Maximum AVAS Sound Pressure Level
• AVAS Sound when vehicle stationary

Status report of the task force on the 02 series of UN R138.

Consolidated text prepared by the QRTV task force (for information).

Proposal for a reference document concerning a general approach for how to handle measurement uncertainties under UN Regulations within the purview of GRBP.

Based on input from Germany, Switzerland, the Netherlands, and OICA.

Report on the status of work to update the ISO standard “Acoustics — Measurement of sound emitted by road vehicles of category M and N at standstill and low speed operation — Engineering method”.

Proposal to address inconsistency between UN R51 noise limits and AVAS sound levels under UN R138.

Proposal to bring the latest ISO 10844 standard test surface into the Regulation.

Consolidated draft revision under development by the UNR138.01 task force.

ISO/CD 16254:2022: Acoustics – Measurement of sound emitted by road vehicles of category M and N at standstill and low speed operation – Engineering method.

Proposal to bring the latest ISO 10844 standard test surface into the Regulation.

Text prepared by the experts of the Informal Working group on Measurement Uncertainties (IWB MU) in order to introduce a general guideline.

Presentation by ISO TC43/SC1/WG42