For well over a decade, drivers around the world have enjoyed better headlights. Adaptive Drive Beam (ADB) moves beyond the old-school binary of high and low beams, taking advantage of modern lighting technology that allows parts of a headlight’s beam to dim for oncoming drivers, reducing glare. In America, the tech contravened Federal Motor Vehicle Safety Standard (FMVSS) 108, which only allowed for high and low beams, but the rule was amended in 2022.
Great! Well, three years later, the only automaker to sell an ADB system in the US is Rivian, and no other car companies have immediate plans to offer this sort of tech here. And except for Rivian, everyone is unhappy about the state of things. So how did we get here?
Mercedes-Benz debuted an early ADB system with the 2009 E-Class, and Audi’s first all-LED Matrix lighting system arrived on the 2013 A8. In essence, the Audi system and those that followed pair a headlight made up of multiple LEDs with a camera mounted in the rearview mirror.
When the car’s high beams are on, the system uses the camera to detect and identify objects ahead and selectively turn off LEDs to shade them. If there’s an oncoming car, you can leave your high beams on, but the section of the beam that would otherwise blind the opposing driver goes dark.
Photo by: Rivian
The upside of such a system is obvious, especially in a world where modern headlights are so damned bright. With ADB, the promise is better safety for the vehicle’s driver, and for everyone else on the road. And, of course, a profitable optional extra for automakers to offer. Naturally, automakers petitioned NHTSA to start looking at amending FMVSS 108 a little over a decade ago, and in 2018, the agency put out a Notice of Proposed Rulemaking outlining its plans. The news was not well received, as evidenced by comments from various automakers and the Insurance Institute for Highway Safety (IIHS).
Rather than follow the globally accepted SAE J3069 standard for ADB, NHTSA decided to create its own standard. According to the IIHS, the problem with this is twofold: First, the ruling attempted to apply some of the original binary low-and-high-beam thinking to FMVSS 108, limiting the potential.
“With ADB, the promise is better safety for the vehicle’s driver, and for everyone else on the road.”
“The proposal would require ADB photometry inside any area shadowed for another vehicle to meet existing FMVSS 108 low beam minima, while the intensity outside of the shadowed area (or when no other vehicles were present) would be subject to the existing high beam maxima,” said IIHS senior research editor Matthew Brumbelow in a 2018 comment to NHTSA. “By attempting to shoehorn ADB into the standards written for static headlights in this fashion, the proposal will prevent ADB systems from realizing both their full visibility-enhancing and glare-reducing potential.”
In other words, we shouldn’t limit ADB to preexisting luminosity levels because when used to its full capability, the tech can allow for even brighter high beams without harming the vision of opposing drivers.
Photo by: Rivian
Second, these requirements would effectively keep existing ADB systems sold around the globe from offering their full functionality to the US market. Some automakers sell ADB-capable systems in the US, but with functionality limited to comply with FMVSS 108. The hope with the amended rule was that a simple software update would allow full ADB functionality, but NHTSA’s standards are such that automakers say they can’t make existing ADB systems compatible. Essentially, to offer ADB in the US, a company would need to build an entirely new system.
That’s what Rivian did, and so far it’s the only one; The electric truck maker’s ADB system debuted with the updated R1S and R1T last year. Whereas some of the latest systems from Audi and Mercedes use over a million LED pixels that can effectively project monochromatic images, Rivian’s system is seemingly simple from a hardware perspective. Each headlight has 35 LEDs carefully affixed on a printed circuit board (PCB).
“FMVSS requests for transition zones, and you need to design the PCB for those transition areas,” explains Carlos Montes Relanzon, Rivian’s senior manager for lighting systems. “Otherwise, if you bring a European matrix, it ain’t going to happen, it’s not going to work. You need to design it for this.”
Photo by: Rivian
Relazon said that Rivian actually tested a pre-existing ADB system from a European OEM and it failed the FMVSS test “miserably.” So the need to develop a system in-house and specific for these regulations was obvious. But, while Rivian only sells cars in the US for now, it tells Motor1 that its ADB system is compatible with European and Chinese standards, so when the day comes, it can offer this tech abroad.
“With FMVSS, there’s a very well detailed test structure, test setup that we need to follow to get approval,” says Relanzon’s colleague Xueming Jiang, a system engineer for lighting. “But for the [European Commission] and China, the test is more subjective. You go onto the public road and drive with people from the approval authority.”
The fact that Rivian was able to create and launch an ADB system in two years is remarkable. Typically, the auto industry moves slowly, but Rivian, being a smaller, newer and less bureaucratic company than mainstream automakers, can get things done more quickly, Relanzon said. There’s fewer layers involved in the decision-making process, and both Relanzon and Jiang describe a healthy collaboration between different teams.
Rivian’s approach to hardware and software also offers a key advantage. The new R1T and R1S debuted a new “zonal architecture,” with fewer, more powerful ECUs grouped together in three geographical “zones” handling all vehicle functions. Relazon explains that the Rivian software team allows the lighting team full access to all the vehicle’s sensors, and zonal architecture allows for very quick iterative updates throughout the development process. At a traditional automaker, making such changes often involves an external supplier, which stretches out the process over months. Rivian can instead do it in minutes.
Photo by: Rivian
This level of integration—both within the company, and within the hardware and software of the vehicle—also means Rivian can push out over-the-air software updates for the lighting system that other automakers simply can’t. Rivian says it plans to constantly update its ADB system, too.
So, Rivian has a head start on everyone else. Other automakers are looking into developing their own US-market ADB systems, but it’s unclear when—or if—we’ll see anything. The IIHS told Motor1 in a statement that NHTSA didn’t update the rule based on any of the comments the IIHS provided.
With FMVSS 108 seemingly set in stone for the foreseeable future, Rivian may remain one of the only automakers to offer ADB in the US. Consider the huge costs/time in developing an all-new ADB system that’s also compatible with global regulations, and weigh that against all the other things automakers have to invest in.
It may be yet more decades before we Americans see the light, so to speak.
