Under multiple conditions, both intercity highways and two-lane country highways the cars adaptive cruise control with randomly slowdown/brakes extremely hard. In one specific instance I was driving home in the middle of the night with a vehicle behind me and with no other oncoming traffic or cars in passing lanes and the adaptive cruise "brake checked" the car behind me, I was able to react and cancel the adaptive cruise and avoid an accident. When adaptive cruise is set it will also aggressively approach the car in front, instead of gradually slowing down it will continue at the set speed until the car realizes it's to close and will slam on the brakes to slow down. When adaptive cruise is turned off the car will slam on the brakes if you attempt to accelerate to pass someone and coast back to set speed. in other words, the car will slam on the brakes to resume the set cruise speed. Fortunately, no cars have been behind me when this has happened. Nowhere does it say that this will happen when using normal cruise control? Speeds and conditions varied from city traffic going 20 - 40 mph, the highway going 55-65 and the interstate going 70-80 mph. some instances were at night others were during the day.

- Cottage Grove, MN, USA