Bright flashing front bike light in daylight - why?

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stu9000

Senior Member
Location
surrey
It isn't about taking umbrage.

This thread, like many others, is trying to impart safety advice to other cyclists. And this thread will be read by others long after we have finished posting to it. If I asserted, on the basis of anecdata and pleas to "common sense", that my St Christopher Medal makes me 1% safer I'd expect to be challenged.

People make assertions in here, over and over, like "flashing lights attract the eye, Thats (sic) why they have them on Emergency vehicles" and I'm interested in understanding the science behind those assertions, given that, for instance, flashing blue lights were introduced with, so far as I can tell, no scientific basis for their design and no consistency globally over colour choice, intensity and flash frequency. Some evidence exists that flashing lights may be effective in attracting attention particularly when they are located in the periphery of vision but the results are not entirely consistent nor conclusive and very little research has been done about the use of such lights on motor vehicles and even less on bicycles.

Yet people make assertions about flashing lights improving rider safety and thousands of cyclists have started using them. Along with St Christopher's?

Glad to read you are not taking umbridge and I do accept your point to a degree. But what kind of evidence would you require? Even quotes from peer review documents are meaningless unless you go and read the source . at some point you have to use your judgement having sifted through the best data you can get your hands on. I think this differentiates from some religious good luck charm. There must be more controversial statements we can debate than whether flashing lights attract the eye. I'm sure one will come along shortly.
 

stu9000

Senior Member
Location
surrey
Where does it all end? Bicycles with flashing lights, cycle riders clothed like a pyschedelic vomit.

True. Tis a mad world. Like the proliferation of road signs even for things like crossing frogs! But I don't want to end up over the bonnet of a half asleep driver so I'm keeping the day glo and my flashers. But we are a bit risk averse and safety conscious compared to our parents I think.
 

GrumpyGregry

Here for rides.
A flashing light during is going to increase the chances of you being seen. Impossible to distinguish by how much, because every situation would be different.

But just look at part of a post I made previously about why things are seen.

A light will add OR enhance one of the following, thus increasing the chance of being seen.
  • Shape
  • Shadow
  • Silhouette
  • Movement
  • Spacing
  • Position
  • Texture
  • Colour
  • Noise
  • Shine
It's very bloody simple.

As an ex , an expert on why things are seen, trust me on this.

I don't get why anyone thinks otherwise, is it a lack of intelligence, or that people just like to argue on cycling forums or what?
On the other hand other experts on why things are seen, and other experts on why things aren't seen, don't seem to agree with you.

But perhaps if you were to link to some scientific literature that supports and explains the basis of your pov rather than just asserting your expertise on the matter the debate could move beyond mere willy-waving?
 

GrumpyGregry

Here for rides.
Your list of factors is interesting, and useful to someone whose primary objective is to pick out a target. Sadly, many drivers are not ex-snipers and can't be arsed to scan the field of view from their vehicle with the same level of scrutiny. I'd go further and suggest that a flashing front light only weakens safety by confirming your status as 'only a cyclist' and the average driver will SMIDGAF you.

GC
Even though the I've met both a few times, and the outcomes have been broadly the same, I find the arrogance of the SMIDGAF-er preferable to the complete incompetence of the SMIDSY who drives in a waking coma.
 

Jameshopper

Active Member
From what i have read in the reports i have looked at, there doesn't seem to be any suggestions that a flashing light in the daylight would actually reduce the chances of being seen. Are you able to provide a link that does?
If not, is the discussion then turning towards whether a flashing light will increase the chances of being seen or not? In this case, i don't see any issue with having one.
 

stu9000

Senior Member
Location
surrey
On the other hand other experts on why things are seen, and other experts on why things aren't seen, don't seem to agree with you.

But perhaps if you were to link to some scientific literature that supports and explains the basis of your pov rather than just asserting your expertise on the matter the debate could move beyond mere willy-waving?

Not willywaving. It is my opinion which you are welcome to disagree with. It is a 'forum' for discussion. To suggest that flashing lights increase your chances of being seen does not seem that controversial to me. Everything from Pelican Crossings to emergency beacons on life jackets use them. Now, I can't point you to the extensive testing and research that has undoubtedly been done so I am resigned to the likelihood that I have not swayed you. Ah well.
 

deptfordmarmoset

Full time tea drinker
Location
Armonmy Way
Personally, when driving I like the early warning that I get from an oncoming cyclist in the dark. A couple of times this year I've had to brake suddenly because an oncoming numpty car driver has begun a cyclist overtake when we're almost opposite. If I don't brake the driver is likely to swerve back into the cyclist. The early warning helps me scan the road for possible dangers to the cyclist. Some, of course, will maintain that I should see the cyclist anyway, etc, but I prefer it.
 

BSRU

A Human Being
Location
Swindon
I remember when I learnt to ride a motorbike, there was a similar debate about whether to ride with lights on or not.
The theory is that lights on mean drivers are more likely to see you but are less able to judge your speed.
 
OP
OP
Ganymede

Ganymede

Veteran
Location
Rural Kent
I think you've answered your own question.
I think you've omitted to read my replies to the other people who raised this point.

My points were:

It was bright sunlight
I could see every other cyclist on the road, none of whom had lights on at all
His light wasn't a normal flashing light, it was a feck off great big blinder like a searchlight
I found him distracting
He is the only person ever in all my cycling or driving that I've ever seen have such a feck off great big blinder of a flashing light on in bright sunlight in the middle of the day, so I thought I mention it.

Not: "everybody who rides in daylight or nighttime with a flashing front light is a massive numpty and I'm a blind fool who wants all cyclists to be invisible and die."

I have thought subsequently that if every cyclist did this in sunlight, it would be bonkers.

*yawns, sleeps*
 
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GrumpyGregry

Here for rides.
Not willywaving. It is my opinion which you are welcome to disagree with. It is a 'forum' for discussion. To suggest that flashing lights increase your chances of being seen does not seem that controversial to me. Everything from Pelican Crossings to emergency beacons on life jackets use them. Now, I can't point you to the extensive testing and research that has undoubtedly been done so I am resigned to the likelihood that I have not swayed you. Ah well.
Is that a fact?
 
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snorri

Legendary Member
is the discussion then turning towards whether a flashing light will increase the chances of being seen or not? In this case, i don't see any issue with having one.
No.
The issue is the unnecessary distraction caused to other road users by the use of a flashing light on a vehicle being propelled in a normal manner and the danger this distraction may cause to other road users.
The fewer flashing lights, ie distractions, we have on the roads the better.
 
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