One day, early in my bicycle commuting career, I was riding home from work. My office was at the top of a hill. There was a busy one way street leading away from the office. It was three lanes wide. At the bottom of the hill, one lane turned right only. One turned left only. The middle lane was shared by the through traffic and right turns. Speed limit 25mph. The right turn led to a much busier and higher speed road - a bad direction for bicycles, but the most popular direction for the cars. I would go straight at the bottom of the hill, into the quiet neighborhood streets that were better for bicycles.
I had learned to avoid riding in a right turn only lane when I wasn't turning, but I had not yet gotten as fierce as I am today. I didn't want to be rude, so I would stay to the right side of the center lane so that cars could pass me in that lane. One day, I was just starting down the hill when someone came up behind me and just LAID on the horn. As we went down the hill, they squealed around me on the left, and as we entered the intersection at the bottom, they turned right. I hit their rear quarter panel pretty hard. They didn't stop. Other cars stopped; nice car drivers came over and picked me up out of the middle of the street. I still have scars.
After that I would take the center of that center lane. There was no reason that a car needed to share that lane with me, going into an intersection at that kind of speed.
On my way to work, going the other direction, on the one way street a block over, climbing that hill? Well, the cross street at the top was also one way, and was a left turn. No one should be turning right there, and my speed was much lower, so I would ride way over on the right side of the road, and let people pass me in the right lane. No problem.
I collected an occasional horn honk, but for the most part I think the car drivers could see why I chose my lane position. And if they didn't figure it out one day, they could figure it out the next. When you are commuting you are riding in the same pack of cars each day, and your fellow commuters get used to you. I used to wear a bicycle helmet painted to look like a ladybug, with googly eyes and pipe cleaner antenna. People would come up to me when I was parking my bicycle at the grocery store or whatever, and say "Oh wow, you're the ladybug bicyclist, I see you every day at <such and such location>!" It's good to be part of your fellow commuter's routine, and to be as cheerful a part of it as possible. Traffic is a cooperative endeavor. If you are predictable and you make them smile, they're more likely to treat you kindly, and that makes life better for everyone. I'd much rather they were saying "Look! A ladybug!" than "Dammit, get out of my way!!!"
