Your ACC system looks directly in front of you for other vehicles. Because it only looks forward, your ACC system may have trouble detecting traffic on curving roads.
In the image to the right, see how ACC’s field of view works when the road curves. Its view may include traffic in another lane. It may also miss vehicles in your own lane. In situations like this, your ACC system may not react appropriately to the traffic around you. In the example, your ACC system may unexpectedly slow down if it detects the semi in the other lane.