My commute has one place where the road forks - the right hand lane gets wider, and eventually a separate lane develops on the right for through traffic, while the left two lanes continue down the left fork. My commute takes me to the left, so as I approach the fork, I take the lane, and move a bit further to the left so that cars taking the right side of the fork can pass me on my right. It is very common that cars will move across to the left lane so that they can pass me on my left, then cut across two lanes of traffic to take the right side of the fork. Some motorists are incapable of passing a bicycle on the right.