The GRE glare task force’s first meeting was held on 23 January, 2025, chaired by Germany’s KBA officer. DVN first wrote about this task force shortly thereafter.
Now, seven meetings have been held, each with 30 to 40 participants representing countries (Japan, Germany, France, India, UK, Canada, Poland, Netherlands, Finland), OEMs, lamp and light source makers, test houses, vehicle technical inspection experts and other associations and agencies like FIA, CITA, and FSD.
There was a meeting last month, on 3 February 2026, and the next one is scheduled for next month, on 13 April 2026. All documents are available online (link opens to the 0th / initial session; subsequent sessions can be selected from the menu on the left).
Three homework teams (HWT) were created during session 2 (20 May, 2025), and an additional one during session 3 on 8 July 2025; these teams are dealing with literature, PTI (periodic technical inspection), UN Regulation № 48 (this team isn’t active right now) and ADB + AFS.
Results of the different homework teams have not been finalized yet, but some discussion results have already been presented and include in meeting summary:
- HWT Literature: here is a non-exhaustive list from the group (refer to TFGP-06-02 for complete status)
- Soil on lens
- Misaim of headlamp is very common, and new cars can show misaim already after 10,000 km of use
Light colour temperature and size of the lamp - Illuminance is a major factor and is connected to headlamp alignment and road geometry
- Weather conditions (wet road)
- Mounting height
- PTI adjustment less accurate and gap between the initial aiming of the headlamps carried out by the manufacturer, and how it is assessed and readjusted at garage and PTI level
- Human factors (population ageing with increased light sensitivity and longer dark re-adaptation time above 40/50)
- No maximum value for illuminance in ECE regulation (50R, 75R, 50L), no upper limit for maximum flux
- No driver awareness of onboard technology: more often than not, drivers are unaware about the onboard systems to manually adjust the aiming of the headlamps. Even if they are aware of these systems, they do not intervene to adjust the aiming. For the same reason, most drivers equipped with advanced systems such as ADB are not aware that they could (and should, in some cases) override them.
- HWT PTI: (refer to TFGP-06-03 for complete status)
The main concern can be summarized by in document TFGP-05-10, containing an analysis from FSD on the regulatory gaps in UN R149 and the current PTI practices, and how these gaps contribute to headlamp misalignment and, ultimately, glare on the road. The case studies demonstrated that the current procedures fail to identify a consistent elbow position. When alignment depends on a point that cannot be reliably measured, the risk of misalignment increases and, with it, the risk of glare. Therefore, UN Regulations need clear measurable definitions for the cutoff and the elbow, applicable both in type-approval and PTI.
Then an aiming method should be better described in UN R149. In parallel to that, a new chapter in UN R48 should be added for PTI (including different fuel tank level, without any passengers, and an easy way to activate the neutral state of AFS to have the cutoff visible)
- HWT on ADB and AFS: (refer to TFGP-06-04) for complete status)
The group have not yet formalized their conclusion, that should be presented in the next meeting on 14 April. The group are preparing a list of elements which could cause glare with an active AFS/ADB system, what are the negative effects to performance of ADB/AFS, and what they identify as possible ADB performance requirement improvement.
Depending on implementation and beam pattern, ADB/AFS can either reduce or increase glare. Also, a weak point for automatic switching systems is their response time, which can cause brief glare spikes. Participants further observed that drivers of vehicles equipped with ADB/AFS rely on such systems and rarely override them, even when needed, and mentioned ongoing studies on the human ability to spot cars coming from around a corner or bend.
In parallel to these homework groups, on 28 January the UK delegate introduced to the group a study (which DVN has analyzed) from TRL, titled: “Glare from road vehicle lighting on UK roads”. It concludes that road geometry as well as pitch and roll of the car are the main factors influencing luminance, and that cutoff sharpness is not a key point, but light from below the cutoff going into drivers’ eyes is the problem. Dynamic levelling could address some of the scenarios about road geometry and topography. However, a question was raised about the effective needs to have as much light emitted as there is now. The maximum installation hight (currently 1.2 m) was also a point for consideration.
GTB are also working independently on glare influence. They’ve established a dedicated task force to review the existing literature in order to categorize different types of glare, identify their causes, and propose potential mitigation measures. The status of its work is summarized in document TFGP-05-07, where a rating is assigned to each cause of glare based on three combined factors: intensity, exposure duration, and frequency of occurrence. The GTB task force are now focusing on defining possible solutions to mitigate the identified glare types, along with preliminary indication on the nature of these solutions (regulatory, technological, etc.). Additional updates will be provided as soon as available.
The Chairman reported finding in an online shop an H7 LED replacement bulb presented as legal, because of an ECE type-approval mark…but in reality, it was an approval to UN R10 (electromagnetic compatibility), with a luminous flux far above the legal limit. The German authorities contacted the shop, and the shop agreed that such illegal products will be removed from the catalogue. He mentioned this information in context of the possibility for countries to prohibit the sale of unapproved parts or equipment, in EU Regulation 2018/858 (Art. 50). Similar issues were noted in Finland, where these products are illegal but can still be found on the market and purchased. It was highlighted the need to improve market surveillance at national levels, and it was suggested raising the issue at GRE to inform all Contracting Parties. IEC stressed the importance of this point and suggested to be in contact with CITA due to their experience on PTI. The participants agreed that checks on illegal retrofits should occur both at the point of sale and during PTI. Since this was unanimously identified as a key aspect to prevent glare, it was agreed to be added to the GRE recommendations.
Next task force meeting will be on 14 April, 2026.
