Driver responsibility when using adaptive cruise control
One main limitation of adaptive cruise control that you need to be aware of relates to driver responsibility. When using the function, you are still required to actively and attentively drive the vehicle. You are responsible for all decision-making, actions and responses that are part of driving.
Adaptive cruise control does not know your intentions or the intentions of other drivers. It cannot predict or identify every potentially hazardous situation that an attentive driver can. It's your responsibility to continuously assess adaptive cruise control's performance and act if necessary. As long as you judge its input to be correct, you can let it guide your driving.
Important
Driving conditions
Assessing adaptive cruise control's performance requires that you take all driving, traffic, weather or road conditions into consideration. For example, if there is poor visibility you may need to increase the distance to vehicles ahead compared to the distance kept by adaptive cruise control. The same applies to maintaining a speed that is safe for the current road and traffic conditions.
Improved convenience
When used correctly, adaptive cruise control can reduce the effort of driving. In some cases, it can compensate for driver errors, such as mistakes caused by lapses of attention or distractions. This potential benefit is a supplement to safe driving practices. It does not reduce or replace the need for the driver to stay attentive and focused on driving safely.
Driver readiness
Using speed- and distance-keeping features can mean you may not use the pedals for long periods of time. However, you must remain prepared and ready to brake or accelerate manually if necessary. Avoid changing your driving posture in ways that can delay your response time.
Speed range for adaptive cruise control
- When using adaptive cruise control, you can set target speeds between 30 and 180 km/h (20-110 mph).
- Adaptive cruise control can be activated above 15 km/h (9 mph), but will then try to accelerate up to the minimum set speed.
- When following another vehicle, adaptive cruise control can stay active below 15 km/h (9 mph).
- In situations where you are driving slowly behind other vehicles, such as in a traffic jam, you may be able to use adaptive cruise control even if your speed is less than 15 km/h (9 mph). This requires a vehicle ahead whose speed your vehicle can match.1
Activation and availability
Several conditions must be met to activate adaptive cruise control. They are related to current traffic and road conditions and the vehicle's system status. Some are related to the vehicle being ready to drive, such as the driver wearing their seat belt and all doors being closed. Others relate to your current driving situation, such as driving at a speed within the speed range for adaptive cruise control. If activation is prevented, the specific reason is typically communicated in the driver information area.
Keeping track of vehicles ahead
One of adaptive cruise control's capabilities is to adapt the vehicle's speed to a vehicle ahead and maintain a certain distance to it. Adaptive cruise control's behavior and ability to track traffic ahead depends on several factors, such as your speed and the speed of the vehicle in front.
- If adaptive cruise control follows a vehicle that comes to a stop, adaptive cruise control slows your vehicle down to a stop behind the other vehicle.
- If you are driving below 70 km/h (44 mph), a stopped vehicle detected ahead of you causes adaptive cruise control to slow your vehicle down to a stop behind the other vehicle.
- However, when driving above 70 km/h (44 mph), a stopped vehicle detected ahead of you is not treated as a vehicle to follow. Adaptive cruise control will not slow your vehicle down and will instead try to maintain your set target speed.
Warning
Stopped or slow vehicles ahead
A stopped vehicle in your lane is a collision risk that requires you to act by braking or steering.2
- At speeds below 5 km/h (3 mph), adaptive cruise control may deactivate when following another vehicle:
- if there is uncertainty whether what's detected in front is a stopped vehicle or another object3.
- if the vehicle ahead makes a turn and leaves your driving path.
Vehicle status and systems
Adaptive cruise control relies on the accurate detection and identification of surrounding traffic and road conditions. This includes using information from the cameras, radars and other sensors. The detection system cannot handle all driving, traffic, weather or road conditions. Read the separate manual sections about detection types, how they work and their limitations to better understand how adaptive cruise control performance can be affected.
- To adapt the speed to vehicles ahead, the vehicle uses a combination of radar and camera detection. Consequently, conditions and limitations of these systems can affect the availability and performance of this feature.
Important
Vehicle faults
Certain vehicle faults can affect the availability of driver support features. Check the vehicle status view for indicated issues if adaptive cruise control is unavailable.
Vehicle alterations
Modifications, repairs and accessory installations can negatively affect or limit driver support features. There is a separate manual section with detailed information on this topic.
Other conditions and limitations
- Adaptive cruise control is primarily intended for use when driving on level road surfaces. It may have difficulty keeping the correct distance to vehicles ahead on steep downhill slopes.
- Driving with a trailer or a heavy load can affect the performance and capabilities of adaptive cruise control .