Chrysler 300 Owner's Manual page 170

170 UNDERSTANDING THE FEATURES OF YOUR VEHICLE
Lane Changing
ACC will not detect a vehicle until it is completely in the
lane in which you are traveling. In the illustration shown,
ACC has not yet detected the vehicle changing lanes and
it will not until it may be too late to take action. ACC will
not detect a vehicle until it is completely in the lane.
There will not be sufficient distance to the lane-changing
vehicle. Always be attentive and ready to apply the
brakes if necessary.