The car was stopped over the traffic divider yellow lanes section on rand rd south of Hicks rd facing north and merged into my lane when I was very close driving the same direction I slowed down once he was in front he slammed on the brakes. That intersection ha a camera. Later I turned on lake cook I pulled next to him and calmly I said I have 2 children in the back seat ...he mumbled something and I smelled a strong odor of alcohol I could tell he was drunk! So I took off.