Well, the horn didn't work too well on the commute home tonight. As I was crossing the Dan Ryan on the Jackson Street bike lane, a shiny black BMW pulled alongside me (on my right; the bike lane is on the left side of the street). I tooted the horn and the driver looked at me then turned right into me as I gave a loooong blast. I had plenty of room so I turned with him, leaving a two-foot scratch along the driver's door. No damage to the bike or rider.
The bike lane was recently extended east of Halsted across the bridge, with plastic pylons to provide a buffer between the bike lane and adjacent traffic. Those pylons were knocked down almost immediately and have not been replaced. Also there is no signage directing motorists to watch for bikes (or, I suppose, directing bikes to yield to turning cars).
Steve