The document provides follow-up information from the SLR 77th session. SLR-77-06/Rev.1 corrects errors and omissions in Reg. 150 and will supersede GRE-94-02, potentially merged with the proposal deleting UI in R150-01 for WP.29 submission in November 2026. Four baseline documents for Stage 2/Step 2 work (SLR-77-08/Rev.1, SLR-77-09, SLR-77-10, SLR-77-07 for Regs. 48, 53, 74, 86 respectively) will be submitted to GRE-94 with presentation slides. SLR agreed to keep Par. 6.21 on conspicuity marking and to renumber paragraphs 5.5 to 5.36. Old transitional provisions are documented separately. Apparent surface definition will replace light-emitting surface. Direction indicator visibility requires further study. Harmonisation text prohibits non-mentioned lamps unless compliant with national requirements. Eleven informal documents will be submitted to GRE-94.
Proposal to amend, restructure, and clarify UN R86:
This presentation analyzes RD-ASEP model performance using test run data from Annex_9_test_runs where both left and right sound were measured. Current model shows 1.3% of measurements above L_exp; without the 2 dB margin this increases to 8.4%. Model overestimates at low speeds and underestimates at higher accelerations. Tyre rolling sound parameters have most influence on results and dominate most of the data set. Optimizing all 13 parameters reduces mean absolute error from 2.1 to 1.1 dB. More high acceleration measurements are needed to reliably calibrate the dynamic component.
The document addresses simplification of the definition of “apparent surface” and single lamp distance requirements in UN R48. It presents a new CAD-based concept defining apparent surface using light emitting surface with clear outer lens disregarded. The document notes that current regulation allows multiple ways to define apparent surface resulting in different distances, with existing approvals having distances significantly larger than 75mm between distinct parts without known safety issues. GTB agrees on simplifying the apparent surface definition to describe function contours as seen by road users, while acknowledging this should not restrict possible designs. The document references a 1999 INF Milano study concluding symmetric appearance is relevant for vehicle identification and larger distances are acceptable for symmetric compared to asymmetric constellations.
The 79th SLR Informal Working Group Meeting will be held 7–11 September 2026 at AP Ichigaya, 8th Floor, AP Ichigaya, Ichigaya Osato Building, 1–10 Gobancho, Chiyoda-ku, Tokyo 102–0076, Japan. A reception is scheduled for 9 September 2026 at 18:00–20:00. The meeting includes sessions on Task Force on Glare Prevention and Task Force on Lamps Under Parked Conditions and Task Force on Autonomous Vehicle Signalling Requirements, though it has not yet been decided whether the latter two task forces will be held during the Tokyo meetings. Participants should complete the registration form.
The draft provisional agenda for the December 2026 session includes adoption of the agenda; UN Global Technical Regulations No. 1, No. 13, and No. 20; children left in vehicles including a new UN Regulation and request for authorization to develop a new UN Global Technical Regulation; UN Regulations No. 11, No. 17, No. 21, No. 22, No. 95, No. 100, No. 127, No. 129, No. 134, and No. 170; collective amendments to UN Regulations that impact automated vehicles; Mutual Resolution No. 1; equitable occupant protection; and other business items including exchange of information on passive safety, UN Regulation No. 0, vehicle automation, software updates, airbags and pyrotechnic systems, child restraint systems, bus frontal protection, and election of officers.
The Informal Working Group on Emergency Door Opening (IWG-EDO) will develop amendments to UN Regulations Nos. 11 and 21 and request authorization to amend UN GTR No. 1 and UN GTR No. 14, with a draft for submission to GRSP’s 80th session. In a second step, it will develop amendments for further post-crash extrication requirements for UN Regulations Nos. 94, 95, 135 and 137 and UN GTR No. 1 and 14, with a draft for submission to GRSP’s 82nd session. The group will be chaired by Germany with the Republic of Korea as Vice-Chair and OICA providing the Secretariat.
The Homework Team on Adaptive Driving Beam/Adaptive Front-lighting Systems prepared a status report identifying elements causing glare in activated ADB/AFS systems, including wet road conditions, external objects obstructing sensors, soiled headlamps, camera positioning, and detection limitations. The report examined literature and expert inputs to determine negative performance effects and recommend improvements such as enhanced detection capabilities, stricter cleaning requirements, increased safety margins, predictive beam adjustment, mandatory motorway ADB usage, and driver instruction on manual override functions. Knowledge gaps and potential research needs were identified for consideration in draft recommendations to the Taskforce on Glare Prevention.