Like Priuskitty said that is for the DRCC (dynamic radar cruise control) to turn the range to long, medium, short, or off.
If OP has some time, Robert Scoble talks about some of the limitations of DRCC at . I believe the PiP Advanced model does NOT come w/lane keep assist (LKA) or lane departure warning (LDW). Scoble is triggering LDW sometimes. I unfortunately have a Gen 2 so I don't have such toys (even though I have every option except leather). I have experienced them in a test drive before though. They were new features on Gen 3.
Correct, pipa lacks LKA/LDW. Also, the only setting which improves traffic throughput over "manual" CC is the "short" variant. Long is basically you asking to get cut off by someone else.
I've got a couple nits to pick with the commentary on the video. In the 4:00 segment on the on ramp the car did not accelerate as he described. It will maintain distance in slowing traffic but it won't stop the car. In my experience, when cut off the car will apply the brakes, beep, and tighten the seat belts. In my experience, it does not behave unpredictably. If there isn't a forward target the car will speed up if going slower than the set speed. When it finds a slower target ahead it will brake to maintain the set distance. In my opinion, he should increase the set distance to accommodate his speed.
This braking uses regeneration if possible, just like pressing the brake pedal. In the Advanced, there is also "impending accident" functionality when the radar determines that a collision is inevitable. It slams on the brakes, tightens the seat belts, and a few other things I don't recall at the moment. This is distinct from the flashing screen and beeping that you get when using DRCC and are approaching a vehicle too quickly. The "impending accident" functionality is operative any time the car is Ready, not just when using the DRCC.
I prefer setting drcc distance to two bars. When a car enters lane in front, with three bars the drcc decels much more aggressively to maintain distance. Conversely I find drcc accels a bit too hard when the coast is clear to return to set speed
Oh - thanks for sharing that. I have been pretty happy with 3 bars, except for the accel too hard problem -- I'll give two bars a try.