EU: Harmonisation agreement

A reader gave some helpful information: For travel if in a foreign country, it seems that for lighting you only need to have some sort of red rear reflector, red rear lamp, white or selective yellow front lamp: http://www.ctc.org.uk/cyclists-library/regulations/international-traffic.

So even for long stays it seems questions of what is allowed/required by the rules in another EU country are moot as long as your bike abides by the rules of your own country. And I suppose it was never a problem to know if a bike was road legal in Germany as all approved equipment has K-numbers, so if it has those you're OK.

The need to know about the technical stuff is therefore probably not present, but I would still like to know, and these rules, as all rules in a society, should be freely available, also to counter possible abuse (read bribes and lobbying). One case in point is that in StvZO/TA, unless I overlooked something, only HID headlamps may have asymmetric beam. Why not halogen? (There are halogen headlamps with such left-right asymmetric beam, but not sure if that's generally allowed and thus that I overlooked something in StVZO or that it's a special approval) If correct, this must be the result of manufucturer-lobbying giving people an incentive to buy such annoying headlamps. Another case is special approvals such as the Edelux + SONdelux dynamo. The latter is not StVZO approved in large wheels (559mm or 622mm) except in combination with the Edelux. Why? Why not with other headlamps? How does such a special approval get granted? We need to know! All approvals should be public, and if there's a special approval the reasons why this has been granted should be made clear.


Update 2015-2-2: For using bicycle lighting designed according to rules from another country, in your own country, there is another rule described also on CTC:

UK lighting regulations (and using lighting devices from other countries)

So according to a European directive, the devices that comply with the equivalent standards from other countries, must be allowed in use if they provide an equivalent level of safety. But what is equivalent level of safety? Flashing lights will not be allowed in Germany and will be considered detrimental to safety so UK compatible flashing lights are not equivalent there. The BS-6102-3's cutoff requirements are more stringent than those in Germany and what is written on the CTC page, that "Germany has arguably the strictest cycle lighting laws in Europe" is therefore not true except by interpreting 'strict' as 'the most rules prescribed' which is not at all relevant to how well devices work, how good the rules are, and not to how strict the rules are regarding not-blinding oncoming traffic. From the cutoff requirement, it's easily argued that the German StVZO headlamps are not equivalent in safety to BS approved headlamps (assuming there is a real difference in glare between 0.7 lux and 2 lux at 10 m from a bicycle headlamp). But this may be moot if there is no limit set to brightness of flashing headlamps in the RVLR (I need to read a bit more in RVLR and check that, but I only see a minimum brightness of 4cd, no maximum, so is a 200 cd flashing headlamp allowed? If so it would mean the cutoff requirement in BS 6102-3 is meaningless as a measure to specify equivalence...).

So now we come to something else: When do bicycle (or other) headlamps become 'too bright'?

More on equivalence, and experienced brightness

Update 2015-3-12: I would say equivalence is the wrong term if the value in BS6102-3 above the horizon (70cd) is too low. It cannot be that a standard gives a certain maximum value and that suddenly 3 times that amount is OK too. Either that number has merit, or it should be changed. That position lamps on cars can be 70cd is also not an argument against 70cd being too low, because of the size of the light emitting surface. This is about luminance and thus how the light is mapped via lenses onto the eyes' photoreceptors.

From the information a reader sent me, it may be possible that the 70cd limit was set to allow a choice of higher output emitters, starting from the 'lowest standardised one' which I suppose would be the one supplied with the lamp and with which it would need to remain below the 70cd limit, and in earlier version of BS6102-3 one could choose emitters from a list in BS 6873. This is not mentioned in the latest official standard (the one I analysed)... But it seems strange to specify a maximum and then allow higher output anyway.

Glare can really only be determined properly by calculation from the reflector/lens specification, or from measurement, and neither are done in any standard that I know of. Headlamp and taillamp size, together with a lux measurement, is only an indication of the glare it produces (but it is enough to understand the reason for why some modern quite small car and bus headlamps are an annoyance, ditto for bike lamps), because light distribution is not even from the emitting surfaces. I deal with this issue in my standard WHS-2015 which I will publish soon...

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