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Does ACC Control Steering?

Does ACC Control Steering?

Adaptive cruise control (ACC) is an advanced version of traditional cruise control. Initially, it was an expensive technology reserved for high-end, luxurious, and state-of-the-art vehicles. 

The good news is that it’s now a common feature in most new cars that you’ll find on the road. 

You might have seen some people cruising in their vehicles without steering. How were they doing it with adaptive cruise control? Does it steer?

Adaptive cruise control accelerates and decelerates your car to match your set speed or that of the lead car, but it will not fully steer the vehicle. However, it works with other Advanced Driver Assistance Systems (ADAS) such as lane-keeping and lane centering assist to keep your vehicle in your lane without your steering input.

Read on to find out how the adaptive cruise control works with driver-assist features in steering your vehicle. 

What’s Adaptive Cruise Control?

The ACC’s most basic form, the cruise control, will only aid drivers to keep their vehicles at the pre-set cruising speed. However, the driver will still control the braking and steering. 

A slightly advanced version of the cruise control is the adaptive cruise control (ACC). It is a driver assist safety feature that uses radar and camera sensors to detect the presence of a vehicle in your lane and adjust your car’s speed to match the lead car’s speed automatically.

Also, with ACC, you can set a specific follow distance or time interval to the vehicle ahead. If the lead car decelerates, your vehicle will also decelerate to match its speed. 

When it accelerates, your car will follow suit up until the speed limit that you’d set earlier. It will also ensure that the distance between the two vehicles remains constant according to your setting. 

How Do Cars With Adaptive Cruise Control Steer?

Adaptive cruise control doesn’t replace a driver’s input but improves safety and comfort. It’s essential for long-distance travel or city traffic as it reduces the chances of fatigue while driving. 

In city traffic or when approaching a red light or a slowing vehicle, the adaptive cruise control will stop your vehicle at a set distance behind the lead car. 

However, you’ll need to pair it with Low-Speed Follow, Stop and Go Traffic Assist, or the Traffic Jam Assist driver-assist features. 

The three perform the same function, and the naming varies depending on the manufacturer. In modern cars, they work together with your adaptive cruise control, and you don’t need to activate them separately. 

However, for cars with adaptive cruise control, steering can, at times, be a bit challenging. Having the adaptive cruise control without other driver-assist features means that you’ll be in charge of the steering. 

On the bright side, here are some ADAS features that work in tandem with the ACC to steer your car.

Lane Departure Warning 

Lane departure warning is a passive driver assist feature that will alert you once your vehicle starts drifting out of the lane. It identifies road divider or lane markings using the front-facing cameras and informs you once it notices that the car’s trajectory takes it out of the lane. 

For lane departure systems, you’ll get a notification or warning through either one or a combination of the following.

  • A sound alert
  • A visual alert on the instrument panel
  • A haptic warning such as a mild steering vibration 

You’ll then have to steer the vehicle back to its intended lane position. 

Lane Keeping Assist

Lane-keeping assist is an upgrade on the lane departure warning. It relies on painted road and lane markings to actively steer your car back to its lane and prevent it from steering into the next lane or off the road. 

The system will occasionally notify you to place your hands on the steering to ensure that you’re not asleep or you’re not in your driver’s seat. 

You’ll receive an audiovisual warning such as “place hands on the steering wheel” every 15 to 30 seconds, and you must do so since a vehicle with adaptive cruise control isn’t a self-driving vehicle. 

Lane Centering Assist

Lane centering assist is a newer, more advanced driver assist feature that keeps your car centered in its lane. It uses automatic steering and corrective measures to make real-time adjustments to your car’s trajectory hence keeping it centered in the lane. 

Cars with lane centering assist plus adaptive cruise control qualify as Level 2 automated driving or semi-autonomous vehicles. 

Lane centering assist is much safer than the lane-keeping assist. But all semi-autonomous vehicles will still need you to be vigilant on the road because the system has the following shortcomings.

Shortcomings of the Lane Centering Assist

As the name suggests, lane centering assist relies heavily on road markings that signify lanes. The system won’t work correctly in the following situations.

Road Sections With No Lane Markings 

Lane centering assist relies on lane markings and will struggle in areas without road markings, such as intersections or rural roads. You need to be very careful on such roads.  

In some cases, like when the markings are partially covered or briefly non-existent, your car will try to guess its trajectory, and it can be hazardous around corners. 

The Lane Is Too Narrow or Too Wide

Driving on a road that has narrow or extra wide lanes that aren’t standard will affect your car’s ability to remain in its lane. The lane centering assist electronics are programmed to work with common road markings and may fail in non-standard roads. 

There’s an Obstacle or Pedestrian on the Road

When using lane keeping and lane centering assists, evading an obstacle or giving room to a cyclist may cause the systems to steer back towards the cyclist or obstacle. 

Additional conditions when lane centering assist may not operate properly

  • Your vehicle is not centered in its lane
  • Unpredictable road conditions such as driving in areas under construction
  • In extreme windy conditions
  • When you’ve made modifications to the steering system without updating the electronics

Final Remarks

Adaptive cruise control is about safety while accelerating, cruising, trailing a vehicle, and decelerating. On its own, it won’t provide any form of steering assistance. But as we’ve seen, you can pair it with excellent driver-assist features such as lane centering assist. 

Only lane-keeping assist and lane centering will work with the adaptive cruise control. You can use the lane departure assist regardless of whether the adaptive cruise control is active or not. 

And remember, driver-assist features are not a replacement for driver responsibility. They have a lot of shortcomings and may not be suitable for winding roads with tight curves and roads without lane marking.

Zach Reed

Hi, I'm the founder of VehicleAnswers.com! Having owned a wide variety of vehicles in my life, I was astounded at how hard it can be to find answers to common automotive questions. Rather than sit idly, I decided to create this website to help others!