You are joining a main road at X and want to go to a or to the right. The road is busy in both directions, so you know you will have a long wait to get a gap on both directions at the same time. To the left, there is a roundabout, about quarter to half a mile - but it is to the left and you want to go to the right. However by safely turning left and going around the roundabout you can easily get on your way to the right a lot quicker.
But is it "cheating and being wrong"?
Yabu - cheating, unenglish and disgusting.
Yanbu - good thinking, common sense and aeareness