Positioning when cycling on a road.

General cycling advice ( NOT technical ! )
Psamathe
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Re: Positioning when cycling on a road.

Post by Psamathe »

Mick F wrote: 22 Nov 2022, 10:06am Many of the lanes round here are not much wider than a single track road, so on the uphills, I tend to find a wider bit to pull over to let the following traffic get past.....
Likewise. But for following vehicles I have learnt not to indicate that I'm pulling in as on several occasions indicating has been the prompt for the following car to accelerate to inches from by rear wheel (as they start to accelerate to pass far too early).

Ian
brianleach
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Re: Positioning when cycling on a road.

Post by brianleach »

I've found since lockdown that the faster the road the further out I sit.

Let me say I avoid A roads like the plague but on faster rural roads I've found that if I sit only 1 metre out from the curb drivers rush past barely crossing the centre line and often shouting obscenities as they pass.

If I sit dead centre it forces drivers to consider the overtaking manoeuvre and they often go fully to the other side of the road.

It may be just me or just Hampshire roads but that is what I've found.
mattheus
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Re: Positioning when cycling on a road.

Post by mattheus »

Vorpal wrote: 22 Nov 2022, 9:19am
LancsGirl wrote: 20 Nov 2022, 8:57pm
Is that actually true?

The only study I personally know of is:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3783373/

Which seems to say the opposite (figure 2). I'm not a statistician, so please tell me if I'm misinterpreted that study. And of course it's only one study, but it's the only one I'm aware of.

It seems to suggest that the way to have the lowest number of close passes is to ride very close to the road edge, without a helmet.
The analysed results suggest that the average passing distance is slightly greater when the cyclist is closer to the kerb. However, the passing distance also varies more (that is the range is greater) when the cyclist is closer to the kerb. So looking at the data, all of the closest passes occurred when the cyclist was closer to the kerb.

All of the passes that left room of 0.5 metres or less, occurred when the cyclist was within 0.75 metres of the kerb.

Personally, I'd take slightly less average distance if it reduced the number of *very* close passes. Although Walker's experiment (which the linked one re-analyses) was one person in one part of the UK, the experience mirrors mine elsewhere.
I'd also point out that when Dr Ian Walker did the actual experiment and ran the first analysis, the conclusion was:
The relationship between rider position and overtaking proximity was the opposite to that generally believed, such that the further the rider was from the edge of the road, the closer vehicles passed. Additionally, wearing a bicycle helmet led to traffic getting significantly closer when overtaking. Professional drivers of large vehicles were particularly likely to leave narrow safety margins.
https://pubmed.ncbi.nlm.nih.gov/17064655/

The 2nd study is a different analysis of the same data. I got rather lost in the statistical jargon before I could form an opinion on whether their analysis was "better" !
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pjclinch
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Re: Positioning when cycling on a road.

Post by pjclinch »

mattheus wrote: 23 Nov 2022, 11:21am
The 2nd study is a different analysis of the same data. I got rather lost in the statistical jargon before I could form an opinion on whether their analysis was "better" !
There is also a riposte to the re-analysis from Walker & Robinson where they quibble with it, but the stats is well over my ability to competently comment.

Pete.
Often seen riding a bike around Dundee...
LancsGirl
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Re: Positioning when cycling on a road.

Post by LancsGirl »

Vorpal wrote: 22 Nov 2022, 9:19am
LancsGirl wrote: 20 Nov 2022, 8:57pm
Is that actually true?

The only study I personally know of is:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3783373/

Which seems to say the opposite (figure 2). I'm not a statistician, so please tell me if I'm misinterpreted that study. And of course it's only one study, but it's the only one I'm aware of.

It seems to suggest that the way to have the lowest number of close passes is to ride very close to the road edge, without a helmet.
The analysed results suggest that the average passing distance is slightly greater when the cyclist is closer to the kerb. However, the passing distance also varies more (that is the range is greater) when the cyclist is closer to the kerb. So looking at the data, all of the closest passes occurred when the cyclist was closer to the kerb.

All of the passes that left room of 0.5 metres or less, occurred when the cyclist was within 0.75 metres of the kerb.

Personally, I'd take slightly less average distance if it reduced the number of *very* close passes. Although Walker's experiment (which the linked one re-analyses) was one person in one part of the UK, the experience mirrors mine elsewhere.
Thanks. I didn't bother digging into the data because:

1. It's only one study by one person etc. Like you say

2. Life's too short.
LancsGirl
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Re: Positioning when cycling on a road.

Post by LancsGirl »

Most of the time my distance from the kerb is dictated by the width of the drainage grates. I'll take a line that's a bit further out from the them. If the tarmac around them is in poor condition, even further out. This means:

1. I'm not in danger of skidding on wet metalwork.

2. and/or being thrown off by a sunken grate/deteriorating tarmac around them

3. My line is a consistent distance from the kerb, so predictable for following/oncoming road users.

Sometimes the road surface sends me further in/out from the kerb. On one of my regular rides some utility company has dug a trench, and the replacement tarmac is a bit rough. But it's exactly where I would cycle, so I have an annoying in or out decision to make. Which does actually change according to traffic/weather/light/which turning I'm taking next.
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Vantage
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Re: Positioning when cycling on a road.

Post by Vantage »

brianleach wrote: 22 Nov 2022, 2:54pm
If I sit dead centre it forces drivers to consider the overtaking manoeuvre and they often go fully to the other side of the road.
I discovered last night that even this isn't good enough.
I overtook a waiting taxi on this one way section with my dog on a lead attached to the bike. Going about 4mph the driver couldn't wait for me to pull into a gap to let him pass and instead squeezed by me with barely an inch to spare. And that's not an exaggeration. Closest pass I've ever had.
https://maps.app.goo.gl/zWAD7r5crHYwyxsL7
It seems we need to stay on the right hand side of the lane to ensure our continuing existence if travelling by cycle.
Bill


“Ride as much or as little, or as long or as short as you feel. But ride.” ~ Eddy Merckx
It's a rich man whos children run to him when his pockets are empty.
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Sweep
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Re: Positioning when cycling on a road.

Post by Sweep »

Vantage wrote: 27 Nov 2022, 10:27am
brianleach wrote: 22 Nov 2022, 2:54pm
If I sit dead centre it forces drivers to consider the overtaking manoeuvre and they often go fully to the other side of the road.
I discovered last night that even this isn't good enough.
I overtook a waiting taxi on this one way section with my dog on a lead attached to the bike. Going about 4mph the driver couldn't wait for me to pull into a gap to let him pass and instead squeezed by me with barely an inch to spare. And that's not an exaggeration. Closest pass I've ever had.
https://maps.app.goo.gl/zWAD7r5crHYwyxsL7
It seems we need to stay on the right hand side of the lane to ensure our continuing existence if travelling by cycle.
In Bolton?
Cycled through Bolton fully loaded a while ago and had several encounters with drivers who seemed peculiarly aggressive. And I've cycled all over the place.
Sweep
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Vantage
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Re: Positioning when cycling on a road.

Post by Vantage »

Sweep wrote: 27 Nov 2022, 3:50pm
In Bolton?
Cycled through Bolton fully loaded a while ago and had several encounters with drivers who seemed peculiarly aggressive. And I've cycled all over the place.
Yep. This is just round the corner from where I live.
Your experience doesn't sound unusual in this dump.
Bill


“Ride as much or as little, or as long or as short as you feel. But ride.” ~ Eddy Merckx
It's a rich man whos children run to him when his pockets are empty.
Bmblbzzz
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Re: Positioning when cycling on a road.

Post by Bmblbzzz »

pwa wrote: 22 Nov 2022, 9:19am
Mick F wrote: 22 Nov 2022, 9:01am
andrew_s wrote: 20 Nov 2022, 11:39pm I normally cycle in the nearside car wheel track, which approximates to a meter from the edge on a straight road, but can vary on bends or near junctions.

a) you are far enough out that a car that doesn't move will hit you, which means that the driver autopilot notices you and overtakes properly.
b) you aren't antagonising the drivers unneccessarily
c) car tyres have swept away almost all of the puncture-causing debris

I'll move out where I consider it useful, such as when approaching a traffic island/pedestrian refuge, and I'll also move in to the edge if a following car has already slowed down to more or less my speed.
+1
Yes, that's about it for me too. Moving into the gutter area is a temporary measure to be done for a few seconds to let past a driver who has slowed right down and has been showing some patience, and who you think best to get in front of you now, while conditions are right. It isn't an area to dwell in for long.
I'd agree too.
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