Just wondering, it says

"Active Cruise Control allows the driver to set a desired speed that is automatically maintained in free-flowing traffic. However, as the 3 Series Sedan approaches a slower-moving vehicle ahead, a radar sensor in the front bumper alerts the system. Active Cruise Control will then act to match the speed of the slower vehicle, and remain a set distance behind, pre-selected by the driver. As soon as the lane ahead is clear, Active Cruise Control automatically returns the car to the set speed.*"

Does this mean that the car breaks for you when you approach a car? so like if someone cuts u off and panic breaks (hypothetical situation) will the cars sensor panic break for you?

it should slow u down to match the speed of the car ahead of u.... unless it's in a situation that even u can save... i'm sure the system was developed to react faster than a human can...

but does it just cut your acceleration or will it actually brake for u?

i remember watching a top gear episode reviewing some S class... think it's S55 or S600... they had something similar to the Active Cruise Control... dono what it's called but it applies the breaks for the car when the engine is not enough to slow down the car... so i think BMW would do the same... apply brakes....

If it works anything like Infiniti's active cruise control (in the FX35/45), then yes, it brakes.

it uses a radar to detect the distance of the car in front of you. then it does numerous things to controll the speed of the vehicle (apply brakes, open or close throttle, etc.) all the driver has to do is steer. also, it detects if an open lane appears helping you automatically pass a vehicle. i'm not exactly sure on the entire system just yet, but it's coming out on the E90 wagons and new cars. i wasn't informed about any abrupt stopping or what would happen if the radar lens was cracked due to flying debris. but i'm sure the driver would have to control the car at that point. technology is advanced enough to aid and make things comfortable for the driver...but we're not at a point where technology will actually make decisions and actually completely take over.

like the morons who thought cruise control meant you could let go of the steering wheel, go to sleep, and the car magically takes you to your destination. believe it or not, it has happened.