In the bicycling portion of my brain, wedged between the Daredevil Lobe and the This Is Good For Me Cortex, there exists much neuronal traffic dedicated to picking a line of travel that keeps me alive. It can be a fine line between being courteous to other traffic and being run off the road. Between making sure motorists are aware of your presence and intentions and causing a flare up of road rage. Nothing like a middle finger fully deployed from a truck revving its engine that then whizzes by you leaving only an inch or two of clearance so that you ruminate the 20x difference in mass and 40x difference in inertia between the Ford Excursion/EnviroDestroyer and you to really make you feel alive.
If I could, I�d always bike in a way that is unobtrusive as possible. I�ll be over as far right as possible on the tarmac to let autos pass. However, there are times when hugging that line will make one�s path of travel quite erratic. Pictured in the photo is an example of the physical narrowing of a roadway, which can happen for all sorts of silly design or design fault reasons. The portion of the road in the foreground has allowance for parallel parking on the right hand side, giving just about enough room for there to be proper bike lane if the city were to put some paint down. Is that a good idea here? Maybe not. It would certainly be a "door" lane (sorry Anna, and RIP Peugeot), and as you can see, it would come to an abrupt end where the road narrows ahead.
One option is to follow the yellow path, hugging the right side the entire way. While this may allow more drivers to pass more easily, it also results in the biker jutting out into the lane resulting in A) car swerving over the yellow line to pass, B) car hitting the brakes, C) bike running into curb, telephone poll, trip to ER, getting $7,000 bill in the mail because hospital missed a number on your ID number, etc. As much as an adventure as C is, sometimes I have prior commitments.
I like follow the red line and make my move to where I�ll have to be riding in the narrower road ahead gradually and early enough to leave some buffer. I like to think this makes cars more conscious of both you and the upcoming change in the roadway. If I know there�s just one car behind me and about to pass, I�ll sometimes hug the right until the road narrows. Aren�t I nice guy? But that�s only if I�m certain there�s just one car. If not, sorry cars. I�ll take my chances on a bird flying out the window.