There are many people that have a hard time driving let alone talking on a phone while doing it. Once I exited a road onto another road, where a car was stopped along the berm. Just as I got near the car it swung onto the road to go the opposite way he was facing. I turned my car hard to the right went off the road and almost ran into a culvert. If I hadn't slowed to go by him, I probably would have smashed right into his drivers door. Yes, he had a phone stuck in his ear. I had just passed a residence where it looked like people were having a party. I figure he missed the place, and was getting directions from one of his buddies, when he cut right in front of me.
I'm not sure that he ever did see me. Driving should take 100% of your concentration, and you can't do that when you are talking on a cell phone.