Self Illumination?

[summerdays]

That would be this report titled Cyclist visibility at night : perceptions of visibility do not necessarily match reality

Yes that's the one ... though I would like to repeat the test with slightly different tests ... such as the cyclist not being in the same place on the circuit and adding in lights too - since a fair number of us do have lights ... and even testing things like flashing and steady lights. In fact there are lots of variations which I would like to try.

 

[Tynan]

does anyone have a top they wear in the dark that is not both reflective and hiviz?

 

[ufkacbln]

does anyone have a top they wear in the dark that is not both reflective and hiviz?

Foska Bones!

Absolutely fantastic jacket!

 

[ufkacbln]

Yes that's the one ... though I would like to repeat the test with slightly different tests ... such as the cyclist not being in the same place on the circuit and adding in lights too - since a fair number of us do have lights ... and even testing things like flashing and steady lights. In fact there are lots of variations which I would like to try.

There was a guy who did similar research in the 70's and found that the most effective clothing was........ a fake Police Uniform!

 

[BentMikey]

Sorry BM - and I don't really want to get into a(nother) long drawn out debate with you on this - but that's not true. Other peiople's lights illuminate reflectives just as well as your own, and I've spotted any number of cyclists wearing a hi viz vest instead of lights purely because their reflective strips were picked up by the headlights of cars on the main road. I'm not arguing with you, just telling you.

I'm sorry, but you're mistaken here, and show a basic misunderstanding of how retro-reflectives work. They only return a strong reflection back along the path it came from, and this is why they aren't particularly visible except when illuminated by lights on the line between your eyes and the retro-reflector, pointing towards the retro-reflector. It's why they are effective with only weak lights pointing at them, but it's also why they are invisible to motorists at side roads. It's possible that motorists lights on the main road are sometimes close enough inline with your eyes to cause a decent return, but that's not very often even here in London.

 

[BentMikey]

There was a guy who did similar research in the 70's and found that the most effective clothing was........ a fake Police Uniform!

Exactly, you don't want to be seen as a a cyclist, but as something that poses risk to the motorist. A Policeman is one, posing as just another vehicle using proper super bright LEDs is another.

 

[Jezston]

I'm sorry, but you're mistaken here, and show a basic misunderstanding of how retro-reflectives work. They only return a strong reflection back along the path it came from, and this is why they aren't particularly visible except when illuminated by lights on the line between your eyes and the retro-reflector, pointing towards the retro-reflector. It's why they are effective with only weak lights pointing at them, but it's also why they are invisible to motorists at side roads. It's possible that motorists lights on the main road are sometimes close enough inline with your eyes to cause a decent return, but that's not very often even here in London.

That isn't true, Mikey - light from car headlights whilst focused onto a fixed spot on the road is actually scattered albeit weakly over quite a wide area, and as you said you only need a little light for reflectives to catch it and jump out - which is why big road signs on the side of a motorway are easily and quite well illuminated with their reflective elements despite being above and to the left of the direction headlights face.

 

[BentMikey]

That isn't true, Mikey - light from car headlights whilst focused onto a fixed spot on the road is actually scattered albeit weakly over quite a wide area, and as you said you only need a little light for reflectives to catch it and jump out - which is why big road signs on the side of a motorway are easily and quite well illuminated with their reflective elements despite being above and to the left of the direction headlights face.

Sorry mate, but that's the same misunderstanding on your part. The light from your headlights is still reasonably inline with your own eyes and the highway signs. That's a far cry from the large difference in angle you get with a car waiting at a side road, which doesn't generate any light pointing towards the cyclist on the major road, and another car on the major road.

 

[siadwell]

From http://en.wikipedia..../Retroreflector:

"A retroreflector is a device or surface that reflects light back to its source with a minimum scattering of light."

"Retroreflectors are devices that operate by returning light back to the light source along the same light direction."

"The observation angle is the angle formed by the light beam and the driver's line of sight. Observation angle is a function of the distance between the headlights and the driver's eye, and the distance to the reflector. Traffic engineers use an observation angle of 0.2 degrees to simulate a reflector target about 800 feet in front of a passenger automobile. As the observation angle increases, the reflector performance decreases."

BUT, bearing in mind that Scotchlite, unlike hard reflectors, uses glass micro spheres:

"Corner reflectors are better at sending the light back to the source over long distances, while spheres are better at sending the light to a receiver somewhat off-axis from the source".

So whilst retroreflectors are much more efficient the closer the light source and observer, Scotchlite may pick up enough light from the envionment to reflect some of it to an observer. But I wouldn't stake my life on it.

 

[gaz]

does anyone have a top they wear in the dark that is not both reflective and hiviz?

Yes, all my tops have neither on them!

What bonus will reflective tape give me over my motorbike like lighting system. which includes side lights.

 

[Rhythm Thief]

You'd be surprised. BM will disagree with me on this, but a hi viz vest gives shape to the area behind your lights and helps prevent them from being mistaken for a distant motorbike, say. Or indeed any other bright lights, which are plentiful on most roads, especially in urban areas. Do any of your lights flash? People with only constant bright lights would be surprised at how easily they blend in with, for instance, a queue of traffic with brake lights on.

 

[gaz]

You'd be surprised. BM will disagree with me on this, but a hi viz vest gives shape to the area behind your lights and helps prevent them from being mistaken for a distant motorbike, say. Or indeed any other bright lights, which are plentiful on most roads, especially in urban areas. Do any of your lights flash? People with only constant bright lights would be surprised at how easily they blend in with, for instance, a queue of traffic with brake lights on.

I have 5 rear lights with 2 being constant and 3 flashing. One of the constant lights is on the rear of my helmet.
From the front I have 2 constant lights and one flashing. One of the flashing is on my helmet.

I think that the position of my lights along with the ones On my helmet, I get some shape that is lost from not wearing a Hiviz vest.

But who says that looking like a motorcycle is a bad thing? I don't always want to be categorised as a cyclist as I often go as fast as the moving vehicles in front of me.

 

[Rhythm Thief]

But who says that looking like a motorcycle is a bad thing? I don't always want to be categorised as a cyclist as I often go as fast as the moving vehicles in front of me.

It's very much a bad thing if someone waiting to pull out of a side road or overtake mistakes your bike lights 20 yards away with those of a motorcycle considerably further away and pulls out thinking he's got plenty of room. It does happen ... Your flashing lights make it unlikely though, and the ones on your helmet, as you say, do the same job as a high viz tabard in this instance.

 

[BentMikey]

You'd be surprised. BM will disagree with me on this, but a hi viz vest gives shape to the area behind your lights and helps prevent them from being mistaken for a distant motorbike, say. Or indeed any other bright lights, which are plentiful on most roads, especially in urban areas. Do any of your lights flash? People with only constant bright lights would be surprised at how easily they blend in with, for instance, a queue of traffic with brake lights on.

I'll disagree, and with evidence. You can't see hiviz behind a decent light:

I accept that hiviz might be visible if you have poor quality lights, fair enough. I don't know how you can suggest that it'll let you differentiate between bicycle and motorbike, since some motorcyclists also wear hiviz. The things that actually let drivers differentiate between bicycle and motorcycle are quite different - they are light intensity for the most part, and then speed secondly. This is fairly obvious if you've ever ridden a bicycle with decent lights, as lots of drivers mistake you for a motorcycle and wait when they needn't.

 

[BentMikey]

Well, I went out to do a test last night, and it turns out that vehicles waiting at T-junctions on the minor road do not illuminate hiviz reflectives on the major road. Vehicles on the main road do not illuminate the hiviz reflectives either.

Here's hiviz, with no source of illumination, no vehicles, and no light by the camera:

Here the same, but with an Exposure Joystick pointing towards the hiviz:

And again with vehicles, including behind the camera, and no torch. There is no illumination of the hiviz vest:

And now with a vehicle at the T-junction, and still no illumination of the vest:

The camera pretty much matches what my eyes saw, and I never once saw the slightest sign of any retro-reflective return with multiple vehicles coming up to that T-junction. Brand new hiviz vest, btw.