The Federal Register on June 26, 2026 published a National Highway Traffic Safety Administration (NHTSA) proposed rule to modernize Federal Motor Vehicle Safety Standard (FMVSS) No. 135, the light-vehicle brake standard. The proposal, docket NHTSA-2026-0728, has comments due July 27, 2026, and follows NHTSA’s June 25 announcement that it would remove hand-operated or foot-operated brake control requirements only for vehicles designed never to be operated by a human.
The limit in the rule text matters. Stopping-distance requirements would stay in place, and automated driving system (ADS) vehicles that retain manual controls would still have to meet the existing requirements. NHTSA also says the brake rule answers whether the vehicle can stop when commanded, not whether the ADS makes the right driving decision. That separate real-world performance question is the reserve issue.
Who it affects
This matters first to self-insured fleets piloting driverless delivery vehicles, campus shuttles, airport circulators, municipal service routes, hospital logistics vehicles, and robotaxis. Captives and public-entity pools may be asked to recognize an autonomous vehicle fleet reserves credit before data matures. Heavy trucking fleets are not the direct target of FMVSS No. 135, which applies to passenger cars and to multipurpose passenger vehicles, trucks, and buses with a gross vehicle weight rating of 3,500 kilograms, or 7,716 pounds, or less. They still face the same governance problem if management imports a pilot credit into a broader commercial auto IBNR selection.
The reserve mechanism
The lever is expected claim ratio and claim frequency. A frequency credit belongs only to the ADS exposure segment, and only when the fleet can support it with credible miles, routes, operating design domains, intervention logs, and crash records. The rulemaking alone does not provide that evidence. NHTSA’s Standing General Order requires certain ADS and Level 2 advanced driver assistance system (ADAS) crashes to be reported when the technology was in use within 30 seconds of the crash, but the public files are not an exposure denominator.
For current accident years, the reserve test should be exposure-weighted: ADS-mile share multiplied by the observed frequency difference, then limited by credibility. If the triangle still blends ADS-only miles with conventional driver miles, a lower selected frequency trend is premature. The diagnostic is separate exposure coding, reported count development, and bodily injury and physical damage severity. Our prior NHTSA ADAS crash-file review made the same point for driver-assist technology, and actuary.info’s ADAS frequency-severity discussion is a useful reminder that safety technology can reduce common crashes while leaving the costly tail unresolved.
There is also a tail-factor caution. Removing a brake pedal does not remove disputed fault. Severe ADS crashes may add product defect, software maintenance, remote assistance, sensor calibration, cyber update, and fleet-operator theories to the liability allocation, slowing closure even if frequency improves. In a line with commercial auto reserve deficiency and a venue-sensitive nuclear verdict severity tail, the first reserve risk is over-crediting new technology before open claims tell the same story.
What this means for your next review
Put ADS segmentation on the reserve-study agenda before changing the pick. Ask whether the auto liability triangles separate ADS-only, ADAS-assisted, and conventional driver exposure; whether the denominator is miles, units, trips, or revenue; and whether case reserves identify product-liability and remote-assistance allegations. The analytical call is straightforward: this proposal may accelerate 2026 and 2027 pilots, but it should not lower carried incurred but not reported (IBNR) unless the fleet’s own ADS exposure is credible enough to measure.
Sources
- Federal Register: Federal Motor Vehicle Safety Standards; Modernization of FMVSS No. 135 To Accommodate ADS-Equipped Vehicles
- NHTSA: FMVSS updates to brake pedal requirements
- 49 CFR 571.135, Light vehicle brake systems
- NHTSA automated vehicles safety resources
- NHTSA Standing General Order on Crash Reporting
- actuary.info: ADAS Creates a Frequency-Severity Paradox for Auto Insurers