if someone is about to undertake you in thhe manner in which BMMF is talking about, I would intentionally drift over to close up the gap, and force them to perform their I'm-a-racing-in-commuter-traffic-dork overtake on the correct side. If they persist in trying to surge on your left, and they clip your back wheel with their front, they're the one who's going down. I find this approach has been very effective, instead of trying to talk to these people, it has just been my instinct to do this recently. Means you are 'moving out of their way' and therefore appearing to be considerate yet actually preventing them from undertaking you, physically. Obviously I am not advocating intentionally clipping their wheel ... if you noticed them too late, you have to hold your line.
if someone is about to undertake you in thhe manner in which BMMF is talking about, I would intentionally drift over to close up the gap, and force them to perform their I'm-a-racing-in-commuter-traffic-dork overtake on the correct side. If they persist in trying to surge on your left, and they clip your back wheel with their front, they're the one who's going down. I find this approach has been very effective, instead of trying to talk to these people, it has just been my instinct to do this recently. Means you are 'moving out of their way' and therefore appearing to be considerate yet actually preventing them from undertaking you, physically. Obviously I am not advocating intentionally clipping their wheel ... if you noticed them too late, you have to hold your line.