This sort of thing is rarer in the UK, but one stretch of road that I use here in Oxford has a seperate bike path (pain to use, covered in glass/debris etc) that runs within view of the road. I have been honked at, ordered, you name - once by a passenger in the car! - it on several occasions by the 1/100 arseheaded motorists that can't stand to see a bike on the road, when the other 99/100 have passed without inconvenience.

I ride the full length of the road in question, and only 1/3 of this distance is catered for by the bike path - the "trouble spot". Perhaps surprisingly, I have never had any argument from motorists on the remaining 2/3, even the steep narrow section that often leads me to cause a slight back-up in traffic. Here I often wave cars through when it is safe and give a thumbs up a gesture that is often couteously returned. Go figure!

Ed