The default position is the middle of the lane.
When a faster vehicle is approaching from the rear and it is safe to overtake, shift into the right wheel track to leave more room and to indicate that you have seen the overtaking vehicle. When the overtaking vehicle has committed to a path and has almost reached you, shift as far right as you can -- that extra six inches might matter. (Before deciding how far right is safe, look to see what you will hit if you fall off the road.)
When it is not safe to overtake, indicate that you have seen the approaching vehicle by putting your left hand out with fingers spread and the palm toward the approaching vehicle. When the oncoming traffic is almost clear, warn the driver that it's about to become safe to overtake by looking back, then shifting into the right wheel track.
When you want to turn left from a multi-destination lane, signal your intention, shift into the left wheel track to leave more space for people who are going straight, and signal again when you reach the intersection. When the light turns green, enter the intersection, then wait for oncoming traffic to clear before turning. (Some traffic lights have a left-turn phase during which the oncoming traffic must wait for you.)
Symmetry suggests that you should shift to the right before turning right, as car-drivers do.
Unfortunately, shifting to the right is an emphatic and unambiguous "now is a good time to overtake" signal. This is all very well if the overtaking driver is going straight; that's why car drivers shift to the right, after all. But right-turning car drivers haven't been taught to get into line behind right-turning bicycles and wait their turn, and they have been taught, unintentionally, that bicycles are stationary objects. If you signal that it's safe to overtake, the right-turning car *will* overtake, and when swerving to the right, it will aim for a point that gives a good three inches of clearance to your current position. You must never approach an intersection farther to the right than the middle of the lane -- so on some occasions, you will shift to the left before turning right
When overtaking a parked car, give it as much room as you give to the oncoming traffic. It is impossible to verify that a car is empty, and if someone is in it, he may open a door at exactly the right time to steer your bike out from under you, and you are more likely to fall into traffic than to fall onto the parked car.
Always leave yourself room to dodge to the right. Sometimes a black spot that you took for a fresh patch of asphalt turns out, when you are too close to stop, to be an open manhole or a sunken drain. Don't ride so far right that you have to choose between crashing by hitting it and crashing by getting run over.
I've left out more than I put in. Keep your brain engaged, use common sense, and don't freeze onto a rule.Back to the cover page