Automatic Emergency Steering (AES)
Automatic emergency steering (AES) is a driver-assistance function that can apply steering input to help avoid or reduce a collision when defined activation conditions are met.
How AES differs from routine steering support
AES is intended for an urgent collision scenario. The system must detect a hazard, assess that steering can help, and identify an available path before intervening. Depending on the design, it may initiate the manoeuvre itself or support an evasive manoeuvre started by the driver. Braking and steering can also be coordinated.
This differs from lane-keeping assistance, which makes routine corrections near lane markings, and from lane centering, which continuously helps hold a chosen position. An AES function may rely on cameras, radar, lidar, ultrasonic sensors, or sensor fusion, but the exact detectable objects and operating range vary.
Emergency steering is constrained by available space, tyre grip, vehicle speed, road edges, nearby traffic, sensor visibility, and the system’s approved operating conditions. A safe escape path may not exist, and an intervention cannot guarantee that a collision will be avoided.
AES is not autonomous driving. The driver remains responsible for observation and control and must be ready to steer or brake. Vehicle documentation should be used to understand whether a marketed feature initiates steering, amplifies driver input, or only warns.
For system types and activation principles, see Automatic Emergency Steering.