I was having a conversation with a fellow rider and we had a difference of opinion about where is the best place to position yourself when riding a four lane road/highway. I tend to stay closer to the center line, that way I'm making myself as visible as possible to traffic to my right (or left). He says it's best to position yourself closer to the shoulder, that way if someone merges into your lane you will have time to adjust. I feel that if you are closer to the shoulder you are less visible to other vehicles and will have traffic merging into your lane more often than not. I'm just curious as to what some of you think is the best position to be, closer to the shoulder or closer to the center line?