Yes, there is a diagram.
This is on my commute to work. I join the motorway from a feeder road with three lanes. The first two lanes take you left on the roundabout (the way I want to go). The third lane takes you round a roundabout to join the motorway going in the other direction. There isn't an option to go straight on. Everyone joins from the same direction on the feeder road, which only goes to the motorway.
There are always long rush hour queues in the first two lanes. Some drivers cut the queues by zooming up the right-hand lane, going all the way around the roundabout and cutting into the queuing traffic joining the slip road.
AIBU to think this is CFery and refuse to let them in?