SAE International have published a revision of their J3134 standard for automated driving system (ADS) marker lamps. These are the blue-green (turquoise) exterior lights intended to advertise to pedestrians, road users, and public safety officials that the equipped vehicle is operating in automated mode.
J3134 is the world’s first comprehensive technical standard for this kind of lamp, and its requirements are closely matched in regulations now under development in China and Europe.
North American Lighting’s Manager of Regulations and IP, Romeo Samoy, brought his expertise to bear, as chair of the Signal and Marking Devices committee within the SAE Lighting Systems Group. They began drafting SAE J3134 in 2015; Samoy says automated vehicles were just a discussion back then: “There was a lot of talk and studies on how automated vehicles should communicate with pedestrians and road users. There were many proposals and questions on how this could be achieved. Now we weren’t sure how to put all of these designs into a single standard, so we decided to focus on just an ADS marker lamp that essentially says, ‘This vehicle is in automated mode'”.
Now a bill in California’s legislature – CA SB 480 – proposes that autonomous vehicles be permitted to display ADS marker lamps in accord with J3134, and AAMVA (the American Association of Motor Vehicle Administrators) now includes ADS marker lamps in their Guidelines for Regulating Vehicles with Autonomous Driving Systems.
This updated version of SAE J3134 extends the specification to side and rear ADS markers (previous versions covered only front ones). It has photometric requirements meant to harmonize with the UNECE TF-AVSR draft proposal, and it is more explicit with regard to lamp activation and deactivation.
Meanwhile, outside the North American regulatory island, the discussion is still open within the relevant UNECE working group as to side ADS lamp minimum daytime intensity (20 candela as in SAE J3134, or only 12 candela as discussed during the latest TF-AVSR in December 2025?). Front and rear intensities seem to be aligned between ECE and SAE: daytime minimum 50 / maximum 300 cd; nighttime 10 to 125 cd, as described in the TF-AVSR document linked above.
There is still a difference with lamp activation and deactivation. ADS marker lights are seen in the US as an auxiliary lamp that must not impair the legally-required light functions – tail lamp, DRL, etc – so when the ADS markers are on, the lights required by FMVSS 108 for whatever conditions are at hand must also be on. In Europe, the current idea is to deactivate the position lamps or DRLs when the ADS marker lights are lit.
SAE have put up a video showing the J3134-compliant Mercedes ADS marker lamps, with nice show-and-tell.
