Non driving cyclists

Commuting, Day rides, Audax, Incidents, etc.
reohn2
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Re: Non driving cyclists

Post by reohn2 »

The Mechanic wrote:
Flinders wrote:..... They make it far harder to see pedestrians, cyclists, and animals.



How?


Bright lights close down the iris,and so make seeing non bright things that much more difficult.
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kwackers
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Re: Non driving cyclists

Post by kwackers »

The Mechanic wrote:
Flinders wrote:..... They make it far harder to see pedestrians, cyclists, and animals.



How?

They don't really make it harder - what they do is make it easier to see cars which means you don't have to look for as long which means you're less likely to see pedestrians, cyclists and animals.
Of course this won't make that much difference until the majority of cars have DRL's since drivers still have to check to make sure cars without DRL's aren't actually moving.
As we approach 100% compliance then risk compensation will begin to kick in reducing the amount of time drivers need to look before pulling out.
Flinders
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Re: Non driving cyclists

Post by Flinders »

Yes they do make it harder. And that's medical fact, not opinion.

If you are driving and the traffic coming the other way has its lights on, the eye will close up, as has been mentioned earlier, making it harder to see anything unlit. It also affects the way you perceive tonal contrast, again making it harder to see anything unlit. It will also make if harder to see colours, as the parts of your vision that see colour won;t operate as well, making even the brightly coloured clothing some of us wear to be seen harder to see.

Next time you're on a road where a lot of drivers have their lights on in good light (like just after the dawn when some drivers haven't yet remembered to switched their lights off) you look for yourself at how difficult it makes it to see anything else when oncoming cars have their lights on, and how much easier it is to see other things when the cars coming the other way have no lights on.

Also, if you can't see a car without lights on in broad daylight

a) you won't see a bike or a pedestrian either
b) you ought not to be driving at all.
John Holiday
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Re: Non driving cyclists

Post by John Holiday »

I think that the point brought out by this thread, is that the average motorist,once they have passed their 'Test', thinks there is nothing left to learn or keep up to date about.
I recently went on an 'older drivers' course which was helpful,having obtained my driving licence 50 years ago!
Being a National Standards Instructor helps to be aware of the perceptions of different road users.
Mark1978
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Re: Non driving cyclists

Post by Mark1978 »

I also never see the point in using sidelights when driving. I don't think I've ever used them with my car. Either it's daylight and the lights are off or it's dark enough to need your headlights on.

They are of course meant for parking on unlit roads and nothing more.
Bonefishblues
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Re: Non driving cyclists

Post by Bonefishblues »

Mark1978 wrote:I also never see the point in using sidelights when driving. I don't think I've ever used them with my car. Either it's daylight and the lights are off or it's dark enough to need your headlights on.

They are of course meant for parking on unlit roads and nothing more.

Agree - pet hate of mine, too. If you can't see or you think others might not see you, put your headlights on.
AlaninWales
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Re: Non driving cyclists

Post by AlaninWales »

Bonefishblues wrote:
Mark1978 wrote:I also never see the point in using sidelights when driving. I don't think I've ever used them with my car. Either it's daylight and the lights are off or it's dark enough to need your headlights on.

They are of course meant for parking on unlit roads and nothing more.

Agree - pet hate of mine, too. If you can't see or you think others might not see you, put your headlights on.

In lit, restricted roads headlights are not required and simply add to the dazzle, obscuring unlit road users such as pedestrians.
Mark1978
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Re: Non driving cyclists

Post by Mark1978 »

However if it's dark they would also be illegal?
Bonefishblues
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Re: Non driving cyclists

Post by Bonefishblues »

Mark1978 wrote:However if it's dark they would also be illegal?

Not necessarily, however restricted roads can have the lights up to 200 yds (or is it mtrs?) apart so there must be an element of judgement exercised, I'd suggest.
The Mechanic
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Re: Non driving cyclists

Post by The Mechanic »

reohn2 wrote:
The Mechanic wrote:
Flinders wrote:..... They make it far harder to see pedestrians, cyclists, and animals.



How?


Bright lights close down the iris,and so make seeing non bright things that much more difficult.



How close does a car DRL have to be to affect the iris in broad daylight? Since this is a "medical fact" I assume someone must know the "facts"
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[XAP]Bob
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Re: Non driving cyclists

Post by [XAP]Bob »

The Mechanic wrote:How close does a car DRL have to be to affect the iris in broad daylight? Since this is a "medical fact" I assume someone must know the "facts"


Not very close - I get badly dazzled by them at 100m range...
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kwackers
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Re: Non driving cyclists

Post by kwackers »

[XAP]Bob wrote:
The Mechanic wrote:How close does a car DRL have to be to affect the iris in broad daylight? Since this is a "medical fact" I assume someone must know the "facts"


Not very close - I get badly dazzled by them at 100m range...

You get dazzled precisely because your iris doesn't close. They're simply not bright enough to have any effect in broad daylight on your iris.
(As bright point lights though they are fairly intrusive.)
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mjr
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Re: Non driving cyclists

Post by mjr »

kwackers wrote:
[XAP]Bob wrote:Not very close - I get badly dazzled by them at 100m range...

You get dazzled precisely because your iris doesn't close. They're simply not bright enough to have any effect in broad daylight on your iris.
(As bright point lights though they are fairly intrusive.)

Not quite: You get dazzled precisely because your iris doesn't close quickly enough.

http://timtrott.co.uk/dark-eye-adaption/ seems fairly accurate to me. It varies from person to person. I suffer from particularly slow adaptation, so I'm fairly quick on the shades and rear-view-mirror prism when driving and I use an old red bike light (or the MrWhite phone app set to red) instead of a torch at night, although at first I didn't understand why that worked better. I feel I'm safe to drive because my "post-dazzle" vision is still legal AFAICT (and no optician has ever suggested otherwise and they all knew about it because it's pretty obvious when they start shining the torch in) and the compensation is that I can read reflective signs at silly distances and see better than most when entering sudden shade such as on tree-lined roads on sunny days.

Here's a more medical description http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0005194/ - basically, the more light, the smaller the opening and the less you see less-lit things around the light source.

If you shine bright lights directly into eyes, it will trigger adaptation, although maybe not enough or quickly enough to matter in most cases.

Bluer lights like LED DRLs seem worse for it and generally are making daytime driving more complicated and a bit more like nighttime driving, where one needs to avoid looking directly at where you expect other people's headlights to be. I don't know why some politicians have been tricked into thinking this is safer than natural light levels.
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Vorpal
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Re: Non driving cyclists

Post by Vorpal »

http://www.dadrl.org.uk/DRLstudies.html

has quite a lot of information about how DRL affect vision.

The effect of lights on vision is not the only reason that cyclists and pedestrians can be harder to see. There is also the silhouette affect; a pedestrian on a crossing is just a dark shape when passing between the headlights of a waiting, oncoming car.
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maff1977
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Re: Non driving cyclists

Post by maff1977 »

a couple of touring cyclists passed me the other day both with their headlights on. it was about 11 oclock broad daylight! dunno what that was all about. :o
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