Primary and secondary position: reasoning?
Posted: 22 Oct 2019, 5:21pm
I first came across the terms primary and secondary position fifteen or twenty years ago. Once they'd been explained to me, I found the terms were new to me but they corresponded more or less with my previous understanding of road positioning gained mostly from experience and a little from books such as Ballantyne's. But the more I think about them, the less I understand; as so often, knowing more leads to the realization of understanding less.
It's probably best to start with my positioning.I happened to be thinking about this on Sunday's ride and decided to actually take some measurements. I was riding on a reasonably wide road (I'd estimate between 5 and 6m) but without centre line. It was pretty quiet, one vehicle passing me every two or three minutes, and dead straight and flat. I stopped in my riding position and found that, as I'd reckoned, I could lay my bike down flat with its tyres in place and about 10-15cm to spare between bar tops and road edge. At home I measured the bike, the tops of my bars are 96cm above the ground so I'm riding just over a metre from the edge of the road (by which I mean, in this case, the edge of the tarmac;* if there were a kerb, edge line or yellow lines, it might be different. If there were parked cars it would certainly be different). I was approximately here: https://goo.gl/maps/uZpCUHn6aBx46A8S6
Where am I taking this position from? I think from a mixture of the road edge, centre line where present and centre of the lane, also probably from the l/h wheel tracks; but mostly from the road edge. On a narrower road, the typical "single lane plus" country road (where bike and car can pass with reasonable care in opposite directions but it's too narrow to overtake; here for example: https://goo.gl/maps/R8aUB9qHCx7aowhs5) I'll might be nearer the edge but also probably closer to the middle of the road. Mind you, I'll probably also be tacking according to where the fewest holes are! And on my street, which is definitely "single lane only" (it isn't physically possible to get car and bike together in the space between parked vehicles, even if one or both are stationary), I'll ride right in the middle. On a busy A-road I'm probably also a metre or so from the edge most of the time.
But then yesterday, road.cc published a piece about primary and secondary position which I'll try to link to later if I can find it again, in which they gave what is apparently British Cycling advice on this. It boiled down to the primary position for cycling being the centre of the relevant traffic lane but it's considerate to move to the left when safe to do so in order to let traffic pass. I remember they did say "never closer than 50cm to the kerb". This is where I lose track of the reasoning. I can only think of a few situations in which it makes sense to ride in the centre of a traffic lane:
- When queuing at lights or approaching a give way line, if you don't want to or don't think it's safe to filter
- If you're fast enough to maintain at least 20mph (I'm not!) you can probably ride like this in the vast majority of urban situations
- Positioning yourself prior to turning right, though I'd personally be further right
- When you really want to use the whole lane, maybe because of a dreadful road surface or to shield (give confidence to) a child, say
So that's actually more of a secondary position, for deliberate use in particular circumstances, according to my reasoning. And the default position would, for me, be somewhere to the left of that, maybe roughly in line with the l/h wheel tracks of most cars. A friend uses a phrase along the lines of "riding far enough out that you force drivers to take notice of and steer round you but far enough in that you don't look as if you're deliberately in their way (even though you are!)".
Anyway, my point in this post is not precisely to discuss actual positioning but get the "bikeability view", see how/if it differs from the BC view and understand the reasoning behind it all, including but not limited to the designation of primary and secondary. Thank you for your patience in reading this long post!
*Yes, this is really the edge of the carriageway not the edge of the road.
It's probably best to start with my positioning.I happened to be thinking about this on Sunday's ride and decided to actually take some measurements. I was riding on a reasonably wide road (I'd estimate between 5 and 6m) but without centre line. It was pretty quiet, one vehicle passing me every two or three minutes, and dead straight and flat. I stopped in my riding position and found that, as I'd reckoned, I could lay my bike down flat with its tyres in place and about 10-15cm to spare between bar tops and road edge. At home I measured the bike, the tops of my bars are 96cm above the ground so I'm riding just over a metre from the edge of the road (by which I mean, in this case, the edge of the tarmac;* if there were a kerb, edge line or yellow lines, it might be different. If there were parked cars it would certainly be different). I was approximately here: https://goo.gl/maps/uZpCUHn6aBx46A8S6
Where am I taking this position from? I think from a mixture of the road edge, centre line where present and centre of the lane, also probably from the l/h wheel tracks; but mostly from the road edge. On a narrower road, the typical "single lane plus" country road (where bike and car can pass with reasonable care in opposite directions but it's too narrow to overtake; here for example: https://goo.gl/maps/R8aUB9qHCx7aowhs5) I'll might be nearer the edge but also probably closer to the middle of the road. Mind you, I'll probably also be tacking according to where the fewest holes are! And on my street, which is definitely "single lane only" (it isn't physically possible to get car and bike together in the space between parked vehicles, even if one or both are stationary), I'll ride right in the middle. On a busy A-road I'm probably also a metre or so from the edge most of the time.
But then yesterday, road.cc published a piece about primary and secondary position which I'll try to link to later if I can find it again, in which they gave what is apparently British Cycling advice on this. It boiled down to the primary position for cycling being the centre of the relevant traffic lane but it's considerate to move to the left when safe to do so in order to let traffic pass. I remember they did say "never closer than 50cm to the kerb". This is where I lose track of the reasoning. I can only think of a few situations in which it makes sense to ride in the centre of a traffic lane:
- When queuing at lights or approaching a give way line, if you don't want to or don't think it's safe to filter
- If you're fast enough to maintain at least 20mph (I'm not!) you can probably ride like this in the vast majority of urban situations
- Positioning yourself prior to turning right, though I'd personally be further right
- When you really want to use the whole lane, maybe because of a dreadful road surface or to shield (give confidence to) a child, say
So that's actually more of a secondary position, for deliberate use in particular circumstances, according to my reasoning. And the default position would, for me, be somewhere to the left of that, maybe roughly in line with the l/h wheel tracks of most cars. A friend uses a phrase along the lines of "riding far enough out that you force drivers to take notice of and steer round you but far enough in that you don't look as if you're deliberately in their way (even though you are!)".
Anyway, my point in this post is not precisely to discuss actual positioning but get the "bikeability view", see how/if it differs from the BC view and understand the reasoning behind it all, including but not limited to the designation of primary and secondary. Thank you for your patience in reading this long post!
*Yes, this is really the edge of the carriageway not the edge of the road.