I've found cyclists to be very courteous and always yield upon my approach.
You see, I have a set of compressed air train horns on my motorhome, just
for cyclists. Depending on their location in the lane I set the blast
timing, duration and loudness. If they are road hogs I usually reserve a ten
second blast of 163 dB about 15 feet from behind. If they are riding the
shoulder or the white line of the shoulder I find a gentle "toot" from a
hundred feet back adequate. In all cases they yield. I've never been flipped
off at all, it's very hard to do when your hands are covering your ears in
agony.

One time I happened across a road race and a group from the peloton crossed
the yellow line, coming right at me. Full air horns for 30 seconds cleared
the lane and caused one of the best pack crashes I've ever seen. Teeth were
spread all over the road like chicklets, flesh was hamburgered and handle
bars were figure 8's.

I have a fair amount of cycling experience both touring and amateur racing.
As a cyclist, I always yield to cars and try not to obstruct the flow of
traffic. In a collision the car will always win. There are real a.sholes on
both sides. Just don't try to be one of them.

Bill