I'm sure many drivers ment to toot a "friendly toot" on their horn, but a second too long and it turns into: "I'm gonna overtake you and I don't care if you are aware of me or not". Also, when I hear the sound of a horn behind me, I can never be sure if it's ment for me, or some other road user (not even necessary for a fellow cyclist).
Then, the other point I wanted to make (apologises if someone has already made it). On country lanes there isn't even room for a cyclist AND a car driver at the same time, or at least, not without the car driver slowing down so that she/he doesn't knock you off the bike.
Then, the other point I wanted to make (apologises if someone has already made it). On country lanes there isn't even room for a cyclist AND a car driver at the same time, or at least, not without the car driver slowing down so that she/he doesn't knock you off the bike.