Rivian has filed a patent for a fail-safe braking system that would allow an autonomous vehicle to bring itself to a controlled stop if the primary brakes fail — addressing one of the most fundamental safety requirements for operating a driverless fleet at scale.
The United States Patent and Trademark Office (USPTO) revealed the filing on Thursday, a year and a half after the EV maker filed the application.
The patent — which was first shared by the Rivian owner and content creator Chris Hilbert (@Hilbe) on X — comes five months after Rivian introduced its ‘Universal Hands-Free’ feature as part of the Autonomy+ advanced driver-assistance system (ADAS).
By then, the company had also significantly expanded the system’s coverage across North America.
CEO RJ Scaringe said during Rivian‘s ‘Autonomy & AI Day’ event last December that “eyes-off” capability would be the next step beyond hands-free driving, with the ultimate goal of achieving Level 4 autonomy.
What the Patent Shows
The patent addresses a key technical requirement for SAE Level 3 autonomous driving: executing a controlled stop if the primary braking system fails, without driver intervention.
Rivian‘s approach uses the existing electronic parking brake as a backup rather than adding a separate redundant brake actuator.
The autonomous controller monitors both regenerative braking and hydraulic friction brakes in real time, triggering automatic failover to the parking brake if it detects component failures, lost communications, or voltage drops.
The system includes two independent voltage sources that power the parking brake. Both voltage sources connect to dual controller area network buses, ensuring communication persists if one bus fails.
Two vehicle motion controllers can assume primary control if the other reports a fault.
The autonomous controller exchanges status messages with friction brake controllers, drive motor controllers, and power supplies at regular intervals.
Any component that stops responding, reports a fault, or loses power triggers an automatic failover sequence.
When regenerative and friction braking remain functional, the parking brake supplements them during the controlled stop.
If the entire driving brake system fails, the parking brake executes the full controlled stop alone while the autonomous controller attempts to steer the vehicle to the roadside.
Integration
The filing includes diagrams for all-wheel-drive (AWD), rear-wheel-drive (RWD), and front-wheel-drive (FWD) configurations, with a flowchart detailing failure detection and controlled stop sequences across all three.
Including multiple drivetrain configurations signals broader application across Rivian‘s lineup.
Current R1T and R1S vehicles use dual-motor or tri-motor AWD setups exclusively.
Rivian‘s upcoming R2 SUV, entering production in 2026, will offer single-motor RWD alongside dual-motor and tri-motor AWD options.
Its smaller R3 crossover, expected in 2027, follows the same drivetrain strategy.
FWD implementation diagrams in the patent extend its application beyond Rivian‘s consumer vehicles to the company’s electric delivery van co-developed with Amazon.
Production models of the EDV have used a dual-motor FWD, with the EV maker recently confirming it will add an all-wheel-drive variant.
Rivian has not confirmed any front-wheel-drive models, suggesting the filing could cover future product development — or potential licensing to other OEMs.
FWD Applications
Rivian has previously said it aims to license technology to automakers beyond the Volkswagen partnership — through which the legacy automaker agreed to invest up to $5.8 billion in the EV maker, as both companies co-develop software architecture to integrate across its brands.
Last November, Software Head Wassym Bensaid told reporters the joint venture is building software solutions that could eventually serve other manufacturers.
In March, Rivian disclosed plans to license autonomous hardware and software capabilities to other automakers, in addition to the electrical architecture already shared through RV Tech.
Volkswagen Group itself produces numerous front-wheel-drive vehicles across its brands, for instance.
These include the upcoming fully electric ID.Polo and ID.1, as VW‘s strategy for affordable, compact electric vehicles centers on front-wheel-drive architectures to reduce costs and maximize cabin space.
Autonomy Progress
Rivian‘s Autonomy platform is currently on SAE’s Level 2 of automation, where the driver is fully responsible for driving the vehicle while it provides assistance.
With the upcoming features, the company aims to reach Level 3, where the system handles all aspects of driving and the driver remains available to take over.
The driver-assistance software currently falls between Tesla’s Autopilot (L1) and the more advanced Full-Self Driving (Supervised), which is gradually moving toward Level 3 autonomy.
Level 4 autonomy is also in the plans, as the EV maker unveiled its custom 5nm processor and transition to in-house silicon.
Universal Hands-Free
Rivian‘s autonomy software currently offers ‘Universal Hands-Free,’ ‘Highway Assist,’ ‘Adaptive Cruise Control’ and ‘Lane Change on Command’ features.
Lane Change on Command performs lane changes on divided highways when the driver activates the turn signal.
Universal Hands-Free allows drivers to operate hands-free on roads with painted or dotted lane markings, though the system will not stop or slow down for traffic lights or stop signs.
The feature rolled out in a major autonomy-focused software update late last year — which included the expansion of the Autonomy platform coverage by 24 times to 3.5 million miles of marked roads.
Earlier this year, Rivian warned owners upon the release that the hands-free assisted driving function “will not stop or slow down for traffic lights or stop signs,” urging them to review the Owner’s Guide for additional details on the feature.
Two additional features are expected later this year, according to the company’s website.
Paid ADAS
Rivian began charging for Autonomy+ earlier this month, ending a free trial period that the company extended three times since December.
The software is available as a $49.99 monthly subscription or a one-time purchase of $2,500 in the United States, and C$69.99 per month or C$3,500 in Canada.
All new R1S and R1T deliveries include a 60-day trial of the system, which also applies to new R2 deliveries — set to begin in the following months.
The autonomy features are only available for second-generation R1 vehicles, with Gen 1 units having the more limited Driver+ assisted driving.
According to the fine print on Rivian‘s website, the one-time purchase option covers the lifetime of feature support for the hardware installed at delivery and transfers with the vehicle upon a change of ownership.
Uber Partnership
Late last month, Rivian disclosed a partnership with Uber that puts a clearer date on that goal.
Under the agreement, Uber will invest up to $1.25 billion in Rivian through 2031, and the two companies plan to deploy up to 50,000 fully autonomous robotaxis across 25 cities in the United States, Canada, and Europe.
Commercial deployment of unsupervised robotaxis is scheduled to begin in 2028.
The partnership is built around the EV maker’s third-generation autonomy platform.
Uber‘s investment is contingent on Rivian hitting autonomous performance milestones by specific dates, though neither company has disclosed what those benchmarks are.
For Rivian, the deal provides a significant new source of capital and guaranteed vehicle demand at a critical moment.
The company is about to start production of R2 at its Normal, Illinois plant, with customer deliveries expected to begin by the end of spring.
