I recognise this from my group rides. We have a guy in our group who just will not be considerate or responsible. Every time we get to a junction or a roundabout most of us will wait if there are cars having the right of way, and then the peloton stops. However, he will then overtake us all, barge right into the roundabout or the junction, so that all the cars stop - mostly when we're riding as a team, the cars will be very cautious. I used to think this was because they want to be considerate, but having seen this guy I'm beginning to think that it's more due to their having seen this type of erratic behaviour... And the result of course is that as all the cars stop, we all feel that we should appreciate their stopping, but you all know how much time it takes to start a peloton, when all have to get back in balance, sort out pedals and so on...