Waymo’s Backup Systems

Waymo’s Critical Safety Systems Have Backups

In the event of a technology failure, Waymo’s system is designed to bring the vehicle to a safe stop. To design its technology to automatically handle faults and failures without relying on a human driver to take back control, Waymo has completed thousands of hours of development and testing.

Waymo has installed backups for its vehicle’s most critical safety systems, which include redundant steering and braking, backup power and computing, and a sensor suite with overlapping fields-of-view.

Backup Computing
A secondary computer in the vehicle is always running in the background and is designed to bring the vehicle to a safe stop if it detects a failure of the primary system.

Backup Braking
If the primary braking system fails, Waymo has a full secondary braking system that immediately kicks in. Either braking system can bring the vehicle to a safe stop if a failure occurs in the other.

Backup Steering
The steering system features a redundant drive motor system with independent controllers and separate power supplies. Either one can manage steering in the case that a failure occurs in the other.

Backup Power Systems
Independent power sources are provided for each of the critical driving systems. These independent power sources ensure that Waymo’s vehicles’ critical driving components remain online during single power failures or circuit interruptions.

Backup Collision Detection and Avoidance System
Multiple backup systems—including independent collision avoidance systems—constantly scan the road immediately ahead and behind the vehicle for objects such as pedestrians, cyclists, and other vehicles. These redundant systems slow or stop the vehicle in the rare event that the primary system does not detect or respond to objects in the path of the vehicle.

Redundant Inertial Measurement Systems for Vehicle Positioning
Redundant inertial measurement systems help the vehicle accurately track its motion along the road. These two systems cross-check each other and assume control from one another, if a fault is detected in either system.