The National Highway Traffic Safety Administration is preparing to overhaul the federal rules governing vehicle headlights as concerns about nighttime glare continue to grow.
The agency says the effort is intended not only to address complaints about increasingly intense headlights but also to modernize regulations that could be limiting the adoption of newer lighting technologies.
NHTSA announced October 6 that it plans to update Federal Motor Vehicle Safety Standard No. 108, the federal regulation covering lamps, reflective devices, and associated equipment.
The review will examine several aspects of vehicle lighting, including LED systems, dusk sensors, automatic beam switching, replaceable light sources, headlamp mounting, and international standards.
The agency also plans to evaluate headlamp height and aim, two factors that can affect how much light reaches an approaching driver’s eyes. That could become particularly important as the U.S. vehicle fleet continues shifting toward taller pickups and SUVs.
NHTSA’s move comes after years of complaints about headlights that drivers perceive as excessively bright. The agency’s latest effort could also create a clearer regulatory path for adaptive lighting systems that can provide stronger illumination while selectively reducing light directed toward other road users.
Why Headlight Glare Has Become a Bigger Issue
Headlight technology has changed substantially since the current federal standards were established. LEDs have become commonplace in new vehicles, while the American market has also shifted toward larger SUVs and pickup trucks.
That combination has changed the nighttime driving environment. A headlamp positioned higher on a large vehicle can direct light toward the cabin and mirrors of a smaller vehicle, while powerful lighting systems can make the exposure more noticeable to an approaching driver.
NHTSA said complaints about glare have increased, prompting the agency to examine whether existing requirements adequately address today’s vehicles and lighting systems. Reuters reported that LEDs now account for most headlights in new vehicles and are generally brighter than traditional halogen systems.
The issue is not simply about maximum brightness. Headlight performance depends on beam pattern, mounting height, aim, road geometry, and the interaction between different vehicles. A technically compliant headlamp can still produce uncomfortable glare under certain conditions.
NHTSA has already studied several of those factors. A recent agency report examined headlamp mounting height, light source, aim, and beam characteristics to determine how they affect forward visibility and glare for oncoming drivers. The agency has also studied how older drivers respond to glare exposure.
That research is relevant because glare can temporarily impair a driver’s ability to see the road and objects outside the illuminated area. At the same time, regulators must balance efforts to reduce glare with another important safety concern, ensuring that headlights provide enough forward illumination for drivers to see clearly.
NHTSA therefore is not simply being asked to make headlights dimmer. The challenge is to improve visibility for the driver using the headlamps while preventing excessive light from reaching other road users.
That distinction is important because research indicates that inadequate nighttime visibility can create a much larger safety problem than glare alone.
The Insurance Institute for Highway Safety found that headlight glare was cited as a factor in only about one or two out of every 1,000 nighttime crashes in 11 states between 2015 and 2023. The same research found that drivers over 70 appeared particularly affected by glare.
The relatively small crash figure does not mean glare is insignificant. It shows why regulators must approach the issue carefully rather than assuming that simply reducing headlight output will automatically improve nighttime safety.
NHTSA Wants to Make Advanced Lighting Easier to Use
One of the most significant parts of the proposed modernization is its potential effect on adaptive lighting.
Adaptive driving beam systems are designed to provide much of the visibility of high beams while automatically creating darker areas around other vehicles. Instead of simply switching from high beam to low beam when another vehicle is detected, the system can selectively modify the beam pattern.
NHTSA already authorized adaptive driving beam headlights in 2022. The agency’s final rule amended FMVSS No. 108 to establish requirements allowing automakers to install the technology on new vehicles.
The technology can be particularly useful because conventional automatic high beams have a relatively simple response. They can switch the entire high beam off when another vehicle is detected. An adaptive system can instead preserve illumination in areas where there is no vehicle while reducing the portion of the beam that would cause glare.
IIHS describes adaptive driving beams as systems that continuously adjust the high-beam pattern to create a shadow around vehicles ahead or approaching from the opposite direction. Research cited by the organization has found lower glare from adaptive systems compared with some conventional headlamp configurations.
Yet the technology has not spread as widely in the United States as it has in other markets. One reason is the complexity of the current American regulatory framework. NHTSA’s new initiative will consider whether the existing rules can be modernized to accommodate newer designs and technologies without compromising safety.
The agency’s regulatory agenda specifically identifies areas including replaceable light sources, dusk sensors, plastic optical materials, semiautomatic beam switching, headlamp mounting orientation, minimum lamp-size requirements, and harmonization with international standards.
That last area could prove especially important for global automakers. Manufacturers often develop advanced lighting systems for European and Asian markets, but differences between regulatory requirements can make it difficult to deploy the same hardware and software in the United States.
NHTSA’s new process could therefore reduce some of those differences and make it easier for automakers to bring advanced lighting systems to American vehicles.
However, the agency’s own testing shows why the regulations cannot simply be removed. In a recent evaluation of European adaptive driving beam systems, NHTSA found that some systems produced glare above derived low-beam limits in certain curves and intersections. Some also struggled to control glare adequately around motorcycles.
That means the goal is not unrestricted use of adaptive headlights. Regulators still need measurable performance requirements that ensure the technology behaves correctly in complicated real-world situations.
Headlamp Height and Aim Will Also Face Scrutiny
NHTSA’s decision to examine headlamp height and aim could be just as consequential as its review of lighting technology.
The growing popularity of full-size pickups and large SUVs has changed the average height of vehicles on American roads. A headlamp mounted considerably higher than the lamps on a passenger car can create a very different glare experience, particularly when the vehicles meet on an undivided road.
Improper aim can make the problem worse. A headlamp designed to provide a carefully controlled beam can produce excessive glare if it is incorrectly aimed upward. NHTSA has previously conducted research into headlamp aim to determine the extent and causes of improper adjustment.
The new rulemaking effort will therefore examine whether changes to mounting and aiming requirements could reduce glare without sacrificing useful road illumination.
The agency is using a negotiated rulemaking process, bringing together experts and stakeholders from vehicle-lighting manufacturers, equipment associations, safety organizations, research institutions, and engineering organizations. Transportation Secretary Sean Duffy is expected to appoint up to 18 participants.
That approach is designed to bring technical expertise into the regulatory process before new requirements are finalized.
It also means drivers should not expect an immediate change to the headlights on vehicles already on the road. NHTSA is beginning a regulatory process, not announcing an instant nationwide brightness limit.
Public comments on the proposed modernization are open until November 9, 2026, according to reporting on the initiative. NHTSA has not provided a final date for when new requirements would take effect.
For automakers, the potential payoff is significant. A modernized standard could allow more sophisticated headlight systems to reach U.S. vehicles while giving regulators better tools to address glare.
For drivers, the ideal result would be headlights that illuminate more of the road without forcing approaching motorists to stare into increasingly intense beams.
That will require more than simply reducing brightness. The most effective solution is likely to involve a combination of better beam control, appropriate headlamp height, accurate aiming, improved automatic systems, and clearer performance standards.
NHTSA’s review is therefore addressing a problem created partly by the success of automotive lighting technology itself. Modern vehicles can illuminate roads far more effectively than older cars, but the same advances can create problems when light is directed toward other drivers.
The agency’s challenge now is to establish rules that preserve the benefits of those advances while reducing their unwanted effects.
If NHTSA succeeds, the result could be a significant change in how American vehicles light the road at night. Drivers could eventually see wider adoption of adaptive beams and other advanced systems, while automakers would gain clearer requirements for deploying them.
The process will take time, but the direction is becoming clear. NHTSA wants U.S. headlight regulations to keep pace with the vehicles and lighting technologies now appearing on American roads instead of relying on rules created for a very different automotive environment.
