Like people have already mentioned, I feel most at risk when the cars are going way faster than me and overtaking from behind, the worst is HGVs overtaking with all those knobbly looking bits that look like they would hook onto your clothes if you were closer.

Also I sometimes find big roundabouts a bit hectic to tackle, having to change lanes can be quite hairy especially on fast roundabouts.normally they are okay if they are small, or big with traffic lights.

Normally on smaller roads the cars don't go that much faster than you so I find that okay.