The legal minimum required to be roadworthy under RVLR perhaps? (I feel like a stuck record
). In setting the standard the governement is telling other road users it's bright enough for a cyclist to be seen by. It is undeniably an evidenced definition and I don't doubt that it was arrived at through research.
I'm sorry, but I don't accept that any such legal minimum standard for lighting or anything else is necessarily sufficient in all circumstances. I think it is foolhardy to trust your life to the principle "because I'm required to have 'that' lamp, that's what I'm going to have and it will be enough no matter what, because the government says it is!". (and based on your next comment, I suspect you might agree with me on that). I'm sure that research contributed towards the setting of the standard - possibly was the main consideration. But I highly doubt if the mandate was to produce a standard that would be fine in ALL circumstances, especially if lighting from other road users has become brighter since the standard was set. I also notice that the standard appears to have been set in 1989, and perhaps, what lights were practicable for cyclists given the technology of the day may have played a role in the decision making. If the standard were reviewed today, would the same levels be set?
I fully respect the right of any cyclist to choose something better than that minimum, I'd even recommend it subject to the maximum. It is refreshing when another road user accepts it is their responsibility to see a cyclist equipped with just the minimum, recent (short) thread here
It was an interesting thread. Morally, I agree with you about responsibility to see any road hazard. And I think any of us, if we ran down, say, a pedestrian dressed all in black, on an winding unlit road at night, in the face of oncoming dazzling headlights - we'd all feel guilty and morally responsible. This would be in spite of the fact that there would possibly have been nothing we could have done to avoid that accident, other than drive everywhere at 5 mph, or stay off the roads altogether after dark. So while such a motorist would probably feel responsible, I think it is quite wrong to blame them for such an accident. The pedestrian in that circumstance has to take some responsibility for being visible! Similar with an unlit or poorly lit cyclist wearing dark clothes and no hi vis. Where you draw the line between 'victim fault' and 'driver fault' however seems to me to be an almost impossible moral question!
Lesaid wrote:So - a key question - what real evidence is there that would tell us how bright really does pose a genuine safety hazard on the roads through dazzling other road users (if properly adjusted)? If we had that, then a sensible strategy might be to formulate some rules of thumb aimed at using lighting a somewhat below that level but not too much below since we don't know how dim is sufficiently visible either!
Have a read here, you'll get a few pointers: https://www.cyclinguk.org/blog/chris-ju ... y-dazzlers
thanks - I read that closely.
You guys have gotten me interested in this topic now, thanks to all the contributions on this thread (thank you
). I'm having a go at analysing the performance of my own front light, to see how it compares with some of the numbers out there - both in lighting pattern, and brightness. Will take a little time though - doing those measurements without purpose-designed and calibrated equipment needs some careful preparation and analysis.
I will also (for my own interest) try to find a lamp of a similar power to the minimum standard, and see how visible it is against car headlights. If it proves clearly visible, I'll eat my words and re-think !! If it isn't, I'll try to find out what it does take to be visible, so far as I can without a specialist lab!