UN R145 and UN R173 establish optional ISOFIX installation for vehicles of category M₂ and M₃. ISOFIX seating positions require compatibility with specific Child Restraint Fixture volumes and lower isofix forward strength of 8kN. I-Size seating positions require minimum 440mm distance between adjacent positions, compatibility with ISO/F2X and ISO/R2, and additional support leg strength testing. The document proposes allowing labels on bus windows and removing marking requirements for M₂ and M₃ from UN R145.

Proposal to modify definitions 2.9 “ISOFIX position” and 2.24 “i-Size seating position”. The revised definition of ISOFIX position specifies which types of ISOFIX child restraint systems as defined in UN R44 and UN R129 may be installed. The definition of i-Size seating position clarifies that such positions are designed to accommodate i-Size child restraint systems as defined in UN R129. The modification bases these definitions on strength test requirements rather than child restraint system category.

ISOFIX position means a position satisfying regulation requirements to allow installation of ISOFIX child restraint systems as defined in UN R44 and UN R129. i-Size seating position means a seating position satisfying regulation requirements to allow installation of i-Size child restraint systems as defined in UN R129.

The document addresses how to define and measure effective seat belt webbing length for buses of category M₂/M₃. It proposes defining effective length by pulling the lap belt at the geometrical midpoint under a 60-degree angle to form an equilateral triangle, where the leg on the buckle side defines 50 percent of pursued effective length for 2-point belts and 25 percent for 3-point belts. Additional webbing for attachment, handling, connection to spool, and spool length must be added based on seat design and geometry. The proposal suggests the definition may work using diagonal belt alone in the ghost position and questions where to include it in UN R173.

Proposed pictograms for CRS installation under UN R107 specify the following dimensions: ISOFIX pictograms with diameter 65 mm, i-Size pictograms with lateral size 65 mm, and RWF CRS in RWF adult seats pictograms with diameter 65 mm.

Initial working draft text to amend UN R107 by inserting a new definition 2.49 for Child Restraint System and adding paragraph 7.7.8.7 to Annex 3 establishing requirements for Child Restraint Systems in vehicles of category M₂ and M₃. Requirements include fitting pictograms to ISOFIX-seating positions meeting UN R145 and UN R173, fitting pictograms to i-Size-seating positions meeting those same regulations, and prohibiting rearward-facing CRS in rearward-facing passenger seats with appropriate pictograms. Three new pictograms are added to Annex 4.

The agenda includes installation of belted child restraint systems, including seat belt minimum length feedback and definition of minimum effective belt length, installation of ISOFIX child restraint systems, amendments to UN R107, ISO pictogram wording revision and dimensions, clarification of the table for M₁ vehicles, introduction of seat belt length requirements for belted child restraint systems on M₂ and M₃ vehicles, amendments to UN R145, ISOFIX force reduction, and proposals to improve ISOFIX definitions across UN Regulations.

The agenda includes installation of belted child restraint systems and seat belt minimum length, amendment to UN R107 per document STCBC-TF173-07-02, amendment to UN R173 per document STCBC-TF173-06-05, and amendment to UN R145 per document STCBC-TF173-07-03.

The agenda for the 10th session of the STCBC Task Force on 22 July 2026 includes adoption of the agenda, amendment to UN R107, amendment to UN R173, amendment to UN R145, and discussion of the next meeting.

The 8th Task Force UN R173 meeting, held 18 May 2026 from 14:30h–16:30h CET via TEAMS, covered welcome and meeting arrangements, adoption of the agenda, amendment to UN R107, amendment to UN R173, and amendment to UN R145, with discussion of the next meeting.

Proposal to insert new definitions for Child Restraint System, ISOFIX position, and i-Size seating position, insert new para. 7.7.8.7 requiring pictograms for ISOFIX-seating positions, i-Size-seating positions, and rearward-facing passenger seats, insert new paras. 10.42 to 10.42.7 establishing transitional provisions with entry into force from the official date, mandatory application from 1 September 2030, and acceptance of prior series until 1 September 2032, and add new figures 33, 34, and 35 to Annex 4 specifying pictogram requirements.

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. 2.9. to redefine ISOFIX position as a position that satisfies the requirements of this Regulation to allow the installation of ISOFIX child restraint systems as defined in UN Regulation No. 44 and UN Regulation No. 129, amend para. 2.24. to redefine i-Size seating position as a seating position that satisfies the requirements defined in this Regulation to allow the installation of i-Size child restraint systems as defined in UN Regulation No. 129, amend para. 5.2.2.7. to state that the requirements of para. 5.2.2.6. do not apply to the i-Size seating position and to low ISOFIX anchorages installed in vehicles of category M₂ or M₃, and amend para. 5.2.4.1. to provide that marking requirements do not apply to vehicles of category M₂ and M₃.

The 9th STCBC Task Force session convenes on 17 June 2026 from 14:30h to 16:30h CET via TEAMS meeting. The agenda includes welcome and meeting arrangements, adoption of the agenda, feedback from GRSP, and amendments to UN R107, UN R173, and UN R145. The next meeting will be scheduled.

Proposal to insert new definitions for Child Restraint System, ISOFIX position, and i-Size seating position, insert new paragraph 7.7.8.7 establishing requirements for Child Restraint Systems including pictogram specifications for ISOFIX-seating positions, i-Size-seating positions, and rearward-facing passenger seats, insert new paragraphs 10.42 to 10.42.7 establishing transitional provisions effective from the official date of entry into force and 1 September 2030, and add new figures 33, 34, and 35 to Annex 4 specifying pictogram requirements.

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.

Proposal to amend para. 2.9. to define ISOFIX position as a position that satisfies the requirements of this Regulation to allow the installation of ISOFIX child restraint systems as defined in UN Regulation No. 44 and UN Regulation No. 129, amend para. 2.24. to define i-Size seating position as a seating position that satisfies the requirements defined in this Regulation to allow the installation of i-Size child restraint systems as defined in UN Regulation No. 129, amend para. 5.2.2.7. to exclude i-Size seating positions and low ISOFIX anchorages installed in vehicles of category M₂ or M₃ from the requirements of para. 5.2.2.6., amend para. 5.2.4.1. to provide that marking requirements do not apply to vehicles of category M₂ and M₃, and amend para. 6.2.5.1. to provide that for vehicles in categories M₂ and N₂ the force shall be 10 times the mass of relevant parts of the seat and for categories M₃ and N₃ it shall be 6.6 times the mass of relevant parts of the seat.