do flashing lights help drivers see you?

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Vorpal
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Re: do flashing lights help drivers see you?

Postby Vorpal » 7 Jan 2014, 7:13pm

Dr. Ian Walker has suggested, in his latest paper (in the March 2014 (how is that available, now?) edition of the same publication) that it may be due to risk compensation.

With bicyclists specifically, Miller (2012), ina case-control study of high-visibility clothing, found no association between wearing high-visibility clothing and reduced crash risk (indeed, there was a small tendency for people with high-visibility outfits to experience more collisions than people without such aids, possibly suggesting a risk-compensation mechanisms is at work).


http://www.sciencedirect.com/science/ar ... 513004636#
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Geriatrix
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Re: do flashing lights help drivers see you?

Postby Geriatrix » 7 Jan 2014, 7:24pm

bogmyrtle wrote:
Geriatrix wrote:Unfortunately this study is hidden behind a paywall but the following quote jumped out in the summary:
In the dark, red/orange/yellow upper body clothing and tail lights increased the odds of a bicyclist-motor vehicle crash.

Tail lights *increased* the odds of a crash?


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Jughead
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Re: do flashing lights help drivers see you?

Postby Jughead » 7 Jan 2014, 8:15pm

Petersen (2012) in his book Just Ride has a chapter entitled "Warning - your blinky light can kill you"
He says that blinking lights causes drivers to fixate on them and then steer towards them. Obviously the difference in speed between bike and vehicle is the reason for so many incidents. Seemingly loads of reflective material is best according to yer man.

I actually use blinking and steady mode lights front and back. Wonder where I fit in? :D

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MissLangley
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Re: do flashing lights help drivers see you?

Postby MissLangley » 29 Jan 2014, 6:53am

If it were in my power I'd ban flashing bike lights at a stroke. It was OK, when they were a way for anaemic LEDs to make their presence felt, with the high output ones on the road now, it's like having photon torpedoes shot in the eyes.

Lights serve two functions, to see and to be seen. In my commute in Cambridge, I encounter many who use extremely bright lights angled up into the faces of oncoming cyclists. I stop them frequently to inform them that I can indeed see their light, but because of the glare I can't see anything else. And then of course, my eyes are below par for a few seconds after. In aggressively pursuing their own safety, these riders are compromising the safety of others. At the extreme are the lights that are so bright (particularly flashing ones) where I cannot bear to look at them, and I've had to look away or shield my eyes. This is a crazy situation.

Most car lights aren't so bad for the eyes, because they're fixed in position and should be on low beam when in traffic. Their light is radiated from a large surface area. Bike lights are now emitting comparable amounts of light from a single source that is tiny. Shinining that in directly in people's eyes is like expecting them to stare at the sun, they will have to look away. Thus the bike light arms races reaches its illogical conclusion.

reohn2
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Re: do flashing lights help drivers see you?

Postby reohn2 » 29 Jan 2014, 9:24am

MissLangley wrote:........... Bike lights are now emitting comparable amounts of light from a single source that is tiny. Shining that in directly in people's eyes is like expecting them to stare at the sun, they will have to look away. Thus the bike light arms races reaches its illogical conclusion.


I think you're right,only yesterday I found myself looking at cyclist's rear light asking myself if it needed to be SO BRIGHT about the size of a 10p piece with a single LED, this thing was far brighter any car stop light and seems to be a popular model with roadies,thankfully it was on a sllooww flash mode,not the fit inducing disco dance mode.
I find it sad that it's come to this state of affairs where cyclists feel the need to 'out shine' other vehicles on the road to get some recognition,however false that sense of security may be.
But it has to be said that there are those driving motors who are so stupid as to begger belief,the antics I witness daily on our roads when cycling and driving,are only being carried out because they are allowed to be.
A good comparison is premiership football.The player knows he he can get away with an awful lot because there's only one referee and no other form of 'policing' on the pitch and that unless a player chops down another in front of that referee he'll get away with it(even if caught out he'll whine and whinge like a schoolboy).
That's because the FA/players/money run the 'show',the tail firmly wags the dog.
This of course can be stopped tomorrow by stricter enforcement of the rules and more policing in the form of cameras and a second ref viewing those cameras which could all but eliminate the 'professional' foul.
The FA and players complain that such measures would spoil the game's flow,etc,which is bunkum because the players would within a very few games realise that they will have to 'play the game' and so the game would become more skillful with less injury as a result.
It's exactly the same on our roads.If road users could be made to see that there's every chance their bad and careless driving/riding would cost them,and also didn't get them from A to B any quicker(which as a rule doesn't) by better refereeing,the roads would be a better place for all of us and the need for sun worship lessened greatly.
Sorry for the ramble but I think it's relevant.........
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Ben@Forest
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Re: do flashing lights help drivers see you?

Postby Ben@Forest » 29 Jan 2014, 11:19am

Jughead wrote:He says that blinking lights causes drivers to fixate on them and then steer towards them. Obviously the difference in speed between bike and vehicle is the reason for so many incidents. Seemingly loads of reflective material is best according to yer man.



I started wearing highly visible (as opposed to hi-vis) jerseys - often with reflective strips - after doing a long tour with a friend. He had two short-sleeve tops, one bright yellow and one black, though it's hardly surprising I could see him so much further ahead on the days he wore the yellow top so I became a convert. I also have to say that I had (and still have) a bright red jersey and a lime green jersey that I thought must really stand out - until someone with colour-blindness told me they didn't. Ouch...

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Re: do flashing lights help drivers see you?

Postby MikeF » 31 Jan 2014, 9:50pm

reohn2 wrote:I don't see many hub dynamo systems in use but a couple of weeks ago I saw a cyclist approaching in the opposite direction when we were out on the tandem.I had to do a double take as I thought it was small motorcycle initially.At a glance,for that's what overconfident drivers tend to do,it would definitely have had the desired effect,and if I were riding in the dark more often I'd be similarly equipped.
The same happened to me in daylight when I was driving the car. Mrs F who was a passenger was convinced it was a motor cyclist approaching until we got nearer. And, no, it wasn't mega lumen dazzle everything in sight so I must be seen type of light, but it was dynamo powered. The visibility was impressive, yet the lamp didn't dazzle. The infuriating thing is you see a few cyclists with highly visible non dazzling lights, but you don't have the opportunity to find out what they are.
"It takes a genius to spot the obvious" - my old physics master

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Re: do flashing lights help drivers see you?

Postby MikeF » 31 Jan 2014, 10:02pm

MissLangley wrote:If it were in my power I'd ban flashing bike lights at a stroke. It was OK, when they were a way for anaemic LEDs to make their presence felt, with the high output ones on the road now, it's like having photon torpedoes shot in the eyes.

Lights serve two functions, to see and to be seen. In my commute in Cambridge, I encounter many who use extremely bright lights angled up into the faces of oncoming cyclists. I stop them frequently to inform them that I can indeed see their light, but because of the glare I can't see anything else. And then of course, my eyes are below par for a few seconds after. In aggressively pursuing their own safety, these riders are compromising the safety of others. At the extreme are the lights that are so bright (particularly flashing ones) where I cannot bear to look at them, and I've had to look away or shield my eyes. This is a crazy situation.

Most car lights aren't so bad for the eyes, because they're fixed in position and should be on low beam when in traffic. Their light is radiated from a large surface area. Bike lights are now emitting comparable amounts of light from a single source that is tiny. Shinining that in directly in people's eyes is like expecting them to stare at the sun, they will have to look away. Thus the bike light arms races reaches its illogical conclusion.

+1
MissLangley wrote:In my commute in Cambridge, I encounter many who use extremely bright lights angled up into the faces of oncoming cyclists.
I've even been dazzled occasionally by a cyclist approaching using a light like this in bright daylight along the local disused railway track!!! The route is motor vehicle free!
"It takes a genius to spot the obvious" - my old physics master

LollyKat
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Re: do flashing lights help drivers see you?

Postby LollyKat » 31 Jan 2014, 11:47pm

MikeF wrote:The infuriating thing is you see a few cyclists with highly visible non dazzling lights, but you don't have the opportunity to find out what they are.

They are probably German - Germany has very strict lighting regulations and their (mostly dynamo-driven) front lights are designed to throw the beam forward and down, but not upwards which would dazzle approaching drivers/cyclists/pedestrians.

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Re: do flashing lights help drivers see you?

Postby RichardPH » 1 Feb 2014, 11:31am

martinn wrote:Hi all,

I ride with high vis, reflectors, and bright lights. I have two 300+ lumen front lights, so I thought that this would be enough for drivers to see me. Obviously not. At a roundabout this am and the previous friday (around 07.15), i have had cars on my left fail to stop, when I am on the roundabout. Today i really though this was it :shock: and i was going to get to work but in a very different form of transport.
So not wishing to become a statistic, would it help if i ran one of the lights in a flashing mode? (I have two currently, one set for the near field and one set for distance, as i ride on unlight cycle paths)

Martin


i strongly suspect that drivers have simply not seen you because of the absurdly thick screen pillars demanded to achieve NCAP5 safety standards. Typical of mechanistic risk analysis, a large part of NCAP seems to consider the after effects of accident, not how to prevent it happening in the first place. In the average modern car you need to move your head around A LOT to see past the pillar, I've 'lost' complete cars, never mind bikes. As the cyclist, the faster you go around the roundabout, the more likely your speed will ensure you remain hidden in the car approaching the roundabout's "pillar blind spot" because your speed nearly matches that of the car.

Most people don't realise this until a near miss or accident occurs, as a driver I count myself amongst the former thankfully.. first time was also in the dark, approaching a roundabout, and it was a fully lit motorcycle that disappeared into my blind spot. Also surprising how easy it is to forget and repeat the whole near miss thing over again, I count myself fortunate not have hit anyone, and yes I ride very defensively on a roundabout. If I don't get recognition of my presence from the driver, then I'm ready for evasive action.

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Re: do flashing lights help drivers see you?

Postby Grumbleweed » 3 Feb 2014, 4:10pm

I always have my bike lights on full beam as I can tell from being a driver that I tend not to see flashing lights till it's too late.

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[XAP]Bob
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Re: do flashing lights help drivers see you?

Postby [XAP]Bob » 3 Feb 2014, 4:19pm

Didn;t volvo start doing space frame structures for the pillars and glazing them?

Oh, just a concept :(
http://www.wayward-volvo.org/drop/volvo_scc.html
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Re: do flashing lights help drivers see you?

Postby martinn » 3 Feb 2014, 9:35pm

Since my original post, I have tried both using a head light and a combining a flashing light with a solid light. The head light seemed to work initially, but I have given up with the head light for a few reasons. The main one being in bad weather, rain or fog, I was getting light reflected back in to my own eyes unless I angled the beam way over to my left. (I don't use a helmet, hence no helmet mount). Having one on flashing and one on solid seems to be the best of "both".
Martin

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Re: do flashing lights help drivers see you?

Postby Grumbleweed » 3 Feb 2014, 10:56pm

I find flashing lights annoying both as a driver and a cyclist. I much prefer full beam as I think other road users do text to see a flashing light as a bit of a target, i.e. obviously a cyclist. Now a blue flashing rear light....