While using the super cruise system I am experiencing unexpected braking of the car as it thinks it is about to rear end the vehicle in the right lane it is passing in the left lane. This happened multiple times on a recent highway drive. I am worried I am going to be rear ended by cars following me or the victim of road rage as it appears to other drivers I am brake checking them while in the passing lane. Additionally the adaptive cruise control and super cruise seem to fail to detect the vehicle immediately in front of me and fails to slow down with adaptive cruise control or attempt to change lanes when using super cruise. In both instances I have to manually brake and or change lanes to avoid a rear end collision. While manually driving the vehicle I am also receiving collision alerts when overtaking cars in the right lane while I am passing them in the left. The super cruise was able to identify cars entering the highway from on ramps multiple times and would auto lane change correctly. This leads me to believe the sensors are working but software may not be utilizing correct distance analysis when slamming on brakes as it passes a vehicle. I am scheduling a dealer service call, but feel like they will tell me there are no computer errors. There are no recalls on file. The on-star monitoring is reporting no errors. Seems like a design flaw, logic error that will require a software update.