Ohh it works, and you can turn it off.
It hasn't brought me to a complete stop, but it definitely has restricted my "aggressive habits". I had a fella in a pickup in front of me signalling left. He merged into the center turn lane and was taking his sweet time. I went to accelerate to briskly move by him in my lane and the car abruptly warned me to brake while I continued to apply throttle pressure. Mind you...I had room, but the vehicle was not happy that the pickup was not 100% out of my line of travel. Even with my foot on the accelerator, the vehicle began to brake and slowed me to about 5mph until he was out of the lane and then gave control back to me.
Was I happy at the time...no. Does it appear to work...yep.