On multiple occasions the forward collision warning and automatic emergency braking have engaged when there is nothing in the lane. On one occasion, the system engaged brakes very hard — which I can only assume was triggered by a pedestrian on a nearby sidewalk. I was traveling 30mph and the vehicle came to an abrubt stop. Traffic behind me was then also forced to slam on their brakes and I feel this could have easily lead to a collision if the driver behind had not been attentive. On another case the vehicle engaged brakes while traveling at 60mph on a two lane highway. I was traveling straight, approaching a rightward bend in the road. My steering wheel was still straight ahead because I had not yet reached the turn. Meanwhile a vehicle was coming the opposite direction around the bend. I believe the system engaged because I was steering straight toward the other vehicle — not taking into account the fact that my lane would bend before reaching it. In this case the system did not stop the vehicle but it did cause a rapid change from 60mph to 40mph in a section of road with no obstructions where neither myself nor drivers around me would expect my vehicle to slam on the brakes. Had the surface been slick such a maneuver could cause loss of control. Again — had drivers behind me not been attentive — I could have been rear ended.