To me, personally, I would want to actually be crystal clear with all the other carpool parents that you feel he’s unsafe and your daughter isn’t allowed in his car for now — use a few recent specific examples of his aggressive driving, and say that YOU would prefer that your daughter didn’t ride in a car driven by the dad. (Don’t say your daughter asked, she can fade into the background as you shoulder the opinion yourself.) If his daughter has another parent, maybe they can drive, or you can have two drivers for the three kids. (In that case, maybe the aggressive driver’s daughter could be picked up at the driver-of-the-day’s house by one of her parents, so you aren’t going further out of your way.) But I wouldn’t just pick her up on Aggressive Dad’s day without another peep, everyone is way too smart (daughters included) for that to fly — everyone will understand the pattern, but maybe not the reason for it, so you might as well speak up.