UN R138 Supplement 1 (02 series) · UNECE Regulation No. 138 (ECE R138) — Uniform provisions concerning the approval of Quiet Road Transport Vehicles with regard to their reduced audibility.
UN R138 — Supplement 1 to the 02 series of amendments
Base text → Supplement 1
- What changed
- During measurement in reverse, the maximum level requirement at the front plane for forward driving must be fulfilled in addition to the rear plane requirement.
- At standstill condition in reverse, the maximum level requirement at the front plane of the vehicle must be equal to that in motion.
- Why
- The expert from Japan prepared the text to clarify the original intent of the TF QRTV conclusion.
- For the front plane when reversing, the old text was not coherent with the TF QRTV limit of 75 dB(A) for standstill and reverse driving.
Q1What changed2 changes
Maximum sound level at the front plane in reverse (para. 6.2.8.)
During measurement in reverse, the maximum level requirement at the front plane for forward driving must be fulfilled in addition to the rear plane requirement. Before this supplement, the text said that the maximum level requirement “in the frontline of the vehicle for forward driving has to be fulfilled in addition”. A new sentence says that, at standstill condition in reverse, the maximum level requirement at the front plane must be equal to that in motion. As before, this can be stated by manufacturer declaration.
Reference to Annex 3 for Table 2a, Table 2b and Table 3 (para. 6.2.8.)
When tested under the conditions of Annex 3 paragraph 3.3.2., a vehicle equipped with an AVAS must fulfil Table 2a, Table 2b and Table 3. A full stop is added after “3.3.2” in this reference. The requirement does not change.
Q2Why it changed
- Proposed by
- Expert from Japan
- Working party
- GRBP, 80th session (September 2024)
Reasons
The expert from Japan prepared the text to clarify the original intent of the TF QRTV conclusion.
Source
“The text reproduced below was prepared by the expert from Japan in order to clarify the original intent of the Task Force on Quiet Road Transport Vehicles (TF QRTV) conclusion.”
For the maximum sound pressure requirement at the front plane when reversing, the old text was not coherent with the TF QRTV consideration. TF QRTV defined the limit value of 75 dB(A) for both standstill and reverse driving.
Source
“the current description is not coherent with the TF QRTV consideration which has defined the limit value of 75 dB(A) for both standstill and reverse driving.”
The new text was added to reflect the original intent and to clarify the limit value agreed by TF QRTV.
Source
“A text has been added to reflect the original intent and to clarify the limit value agreed by TF QRTV.”
Document trail
- 2024-07ProposalECE/TRANS/WP.29/GRBP/2024/20Proposal by the expert from Japan
- —Working party adoptsECE/TRANS/WP.29/GRBP/78GRBP session report, para. 16
- 2024-12Sent to WP.29ECE/TRANS/WP.29/2025/4Text that GRBP sent to WP.29 and AC.1
- 2025-03WP.29 adoptsECE/TRANS/WP.29/1184Adopted at the 195th session (session report, para. 109)
- 2025-09-26In forceC.N.526.2025.TREATIES-XI.B.16.138UN depositary notification
Q3Who is affected
Vehicle manufacturer
- No direct action for this role.
Component supplier
- No direct action for this role.
Technical service / Approval authority
- No direct action for this role.
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ⓘ This report gives advice only. It is not legal or type-approval advice.