Origamist said:For a lot of cyclists, undertaking is considered more convenient (no need to overtake, use the opposing lane and then cut back in) and is also perceived as being less risky - it's therefore not really "amazing" that the majortiy of cyclists prefer to undertake rather than overtake.
And, of course, bike lanes encourage undertaking. My personal beef is not people undertaking as such but when you see cyclists attempting to squeeze up the insides of motor vehicles of all shapes and sizes even when there is absolutely no space to do so. Apart from being downright dangerous, it just looks rude, like you're trying to shove past someone in the post office queue.