UN R173 Supplement 2 (01 series) · UNECE Regulation No. 173 (ECE R173) — Uniform provisions concerning the approval of the Installation of safety-belts, restraint systems, child restraint systems, ISOFIX child restraint systems and i-Size child restraint systems.
UN R173 — Supplement 2 to the 01 series of amendments
Supplement 1 → 2
- What changed
- The Regulation is now amended to account for vehicles of category X, and it does not apply to vehicles of category Y.
- For category X, a seating position with steering control in front may be designated for Child Restraint Systems if paragraphs 5.1.9.2. to 5.1.9.4. are fulfilled.
- For category X, a front passenger seat is now defined from the "R" point of the most forward passenger seat instead of the driver's R-point.
- Why
- The Regulation was originally drafted for vehicles with driver and manual driving controls.
- The amendment intends to keep the spirit of the Regulation and to extend its application to vehicles without driver and manual driving controls.
- The proposal was prepared to enable the application of the Regulation to vehicles equipped with an Automated Driving System (ADS).
Q1What changed31 changes
Section 0. for supplement 2: vehicles of categories X and Y and ADS (paras. 0.4. to 0.4.3.)
New paragraph 0.4. is a heading for supplement 2 to the 01 series of amendments. It says that the Regulation is amended to account for vehicles of category X, and that vehicles of category Y are not in its scope. Without a driver or manual driving controls, provisions related to them must not be taken into account if this amendment does not already cover them. For vehicles with an Automated Driving System (ADS) other than vehicles of category X, no special provisions or exemptions apply in the manual driving mode. In a mode where an ADS feature is active, the relevant ADS requirements apply.
Section 0. text for the original version, the 01 series and supplement 1 (paras. 0.1. to 0.3.3.)
New paragraph 0.1. is a heading for the original version of UN Regulation No. 173. The text on splitting UN Regulation No. 16 is now paragraph 0.1.1., and its list items are now (a) to (c). The paragraph that starts “This UN Regulation consists of” is now paragraph 0.1.2. New paragraph 0.2. is a heading for the 01 series of amendments, with paragraphs 0.2.1. to 0.2.3. Paragraph 0.2.3. says that these amendments mitigate the negative effects on the safety of the occupants by limiting the slack of the buckle belt. New paragraph 0.3. is a heading for supplement 1 to the 01 series of amendments, with paragraphs 0.3.1. to 0.3.3.
New paragraph 1.2. on vehicles of category Y and numbering in section 1.
New paragraph 1.2. says that this Regulation does not apply to vehicles of category Y. The first paragraph of section 1. is now numbered 1.1., and the existing paragraphs 1.1. to 1.4. are now subparagraphs (a) to (d).
Front passenger seat for vehicles of category X (para. 2.16.1.)
A "front passenger seat" is any seat whose "foremost H-point" is in or in front of the vertical transverse plane through the driver's R-point. For vehicles of category X, the "R" point of the most forward passenger seat must now be taken instead of the driver's R-point.
Child Restraint System at a seating position with the steering control in front (para. 5.5.)
For category X, a seating position with steering control in front may be designated for Child Restraint Systems if paragraphs 5.1.9.2. to 5.1.9.4. are fulfilled. These paragraphs define the requirements for a passenger seating position.
Annex 5 table: lap belt text for rows N2 and N3 and new note Z
In rows N2 and N3, “and for the driver's seat” is replaced by “or for a seat having a steering control in front”. The lap belt text of these rows now calls note Z after “windscreen”. New note Z: for this Regulation, in vehicles of category X, the front exterior forward facing glazing or surface is deemed to be a windscreen.
R.E.3 references in footnotes (sections 0. and 1., paras. 2.12.5. and 4.4.1.)
The footnotes to sections 0. and 1., paragraph 2.12.5. and paragraph 4.4.1. now refer to document ECE/TRANS/WP.29/78/Rev.8 instead of Rev.7. This document is the Consolidated Resolution on the Construction of Vehicles (R.E.3).
Q2Why it changed
- Proposed by
- Expert from Germany on behalf of the GRSP Task Force on Automated Vehicles Regulation Screening (TF-AVRS)
- Working party
- GRSP, 78th session (December 2025)
Reasons
The Regulation was originally drafted for vehicles with driver and manual driving controls. The amendment intends to keep the spirit of the Regulation and to extend its application to vehicles without driver and manual driving controls. The proposal was prepared to enable the application of the Regulation to vehicles equipped with an Automated Driving System (ADS).
Sources (4)
“The Regulation was originally drafted for vehicles with driver and manual driving controls”
“it is the intention of this amendment to keep the spirit of the regulation and to extend its application to vehicles without driver and manual driving controls”
“to enable the application of the regulation to vehicles equipped with an Automated Driving System (ADS)”
“See paragraph 0. in the proposal.”
WP.29 reaffirmed its objective to adopt all documents on the review of existing UN Regulations related to ADS at its June 2026 session.
Source
“WP.29 reaffirmed its objective to adopt all documents related to the review of existing UN Regulations related to Automated Driving Systems (ADS) at its June 2026 session”
Document trail
- 2025-09ProposalECE/TRANS/WP.29/GRSP/2025/25Proposal by the expert from Germany on behalf of TF-AVRS
- —Amended in sessionGRSP-78-41TF-AVRS changes to ECE/TRANS/WP.29/GRSP/2025/25
- —Working party adoptsECE/TRANS/WP.29/GRSP/78GRSP session report, para. 43 and Annex XXII
- 2026-04Sent to WP.29ECE/TRANS/WP.29/2026/71Text that GRSP sent to WP.29 and AC.1
- —Amended in sessionWP.29-199-10Amendments for the AC.1 vote, reproduced in Annex VI of ECE/TRANS/WP.29/1192
- 2026-06-24WP.29 adoptsECE/TRANS/WP.29/1192Adopted at the 199th session (session report, para. 103)
- PendingIn forceDate not yet known
Q3Who is affected
Vehicle manufacturer
- Before designating a category X seat with steering control in front for Child Restraint Systems, check 5.1.9.2. to 5.1.9.4.
- For category X vehicles, find front passenger seats with the "R" point of the most forward passenger seat (paragraph 2.16.1.).
Component supplier
- No direct action for this role.
Technical service / Approval authority
- Do not apply this Regulation to vehicles of category Y (paragraph 1.2.).
- For category X vehicles, check front passenger seats against the "R" point of the most forward passenger seat (paragraph 2.16.1.).
- Without a driver or manual driving controls, ignore related provisions unless this amendment already covers them (paragraph 0.4.2.).
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ⓘ This report gives advice only. It is not legal or type-approval advice.