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The interminable argument – daytime riding lights and hi-vis clothing

The interminable argument – daytime riding lights and hi-vis clothing

(First published 22 September 06 on

If there is one thread on that I dread reappearing, it’s the regular discussion about whether or not to wear hi-visibility clothing and to use daytime riding lights (DRL). Partly because although it’s all been said many times, there is always someone who hasn’t read the arguments and refuses to listen to any rational argument.

The issue resurfaced in the last 10 days or so (last done to death in January) and has been rumbling on as it always does – it’s an interminable argument, but it’s one where there should be no winners or losers. It shouldn’t be about taking “sides” but an issue where ideas are examined logically. But for some reason, it always ends up with an “it’s obvious – if you wear hi vis people will see you easier” / “no they won’t” kind of argument.

Those who approach the issue with a closed mind won’t learn anything, except to discover the surprising degree of conflict between those who believe they are safer using visibility aids and those who think that the benefits are exaggerated.

I’d been intending to write something about this for a while, if only to save me having to re-state the same points over and over. However, this letter from Stuart Downie pushed me over the edge:

“I have been reading your rider hints and I read the item about being seen. I have no argument about it except that you do not mention dress. I see many riders, dressed in traditional black, disappear on suburban roads as they get lost in the light scatter from street lights, shops other vehicles lights and shadows. Perhaps it is because I am getting on a bit in years and realise I am mortal but I like to be seen and dress in yellow, with reflective bands if possible. It may not be ‘cool’ but I think it helps ensure that I WILL be seen. They can stick fashion I prefer safety.

“I hope you don’t think I’m being picky but I do wonder how many SMDSYs are the result of dark clothing.”

At the risk of being picky myself, why do the people who believe hi-vis is good always assume that those who don’t wear it do so as a matter of “fashion”?

Anyway, onto the meat of the matter.

The problem with hi-vis kit is that a lot of the time it isn’t.

We’ll start with what should be a very obvious fact that the driver has to be in a position to see the rider or no conspicuity aid can work; the driver has to look in the direction of the rider, has to be able to see past obstacles like the door pillars and roadside furniture.

Even if the driver is in a position to see the rider, he has to recognise “bike and rider”, remember what he is seeing when it matters and correctly judge speed and distance to estimate “time to collision”.

Nor does it automatically follow that because it’s bright or reflective, it’ll show up.

One major issue is that the brain works by subconsciously recognising a pattern and flagging the conscious, decision making mind to sit up and pay attention. This means two things. The brain has to be “tuned” to the shape of a bike and rider. And by using different coloured vests and daytime lights, it has the effect of adding extra “edges” to the shape and potentially breaking it down into smaller shapes that are NOT meaningful.

Just like you can see a bit of plastic lying on the floor and only when you have thrown it away do you realise that it was the battery cover off the TV controller, because taken out of context with the complete unit it was unrecognisable, so the unconscious mind simply never flags the splashes of light and patches of colour as a motorcycle plus rider. This technique has been known about for years as a way of hiding something in plain view – it’s called dazzle camouflage and was very successfully used during the wars to break up the outlines of ships on the horizon and buildings and docks from the air.

Fluorescent kit only works in daylight. In fact, at night under sodium lighting, an orange vest can appear brown. And hi-vis will only show up against a background that provides a contrast. An orange bib will not show up against an orange background like an RAC van, and a yellow bib will not show up against spring foliage.

Think about which bits of a fluorescent jacket show up. The most visible bits of the rider from front and rear, particularly if you have a fairing and a top box, are tops of the shoulders and arms; from the sides just the arms.  Of course, if you have a passenger on the back, the rider is almost completely obscured from behind. A standard hi-vis vest of the sleeveless sort commonly worn is pretty useless on a bike with a screen and a top box. A full sleeved jacket would be better, or something like my old Scott jacket with bright hi-vis yellow sleeves. Light-coloured gloves can be easy to spot because they tend to sit wide of the body of the bike and you tend to move them – even small movements attract attention.  Or you could try leggings rather than a vest. Guess what – noone does – I wonder why?

And everyone and his dog (literally – I saw a dog wearing a fluorescent yellow coat the other day) is now covered in hi-vis paint or reflective stripes, so the “oooh, look at that” factor that once worked (apparently) is lost. Arguably, the most visible colour for a fluoro vest is pink, for the very reason that hardly anything on the roads is pink – and aside from carnations, it’s not that common in nature either! Funnily enough, you don’t see many riders wearing pink – another “fashion” problem I guess.

Even if you don’t succeed in camouflaging yourself with hi-vis, don’t forget the retro-reflective stuff found on only works when illuminated, which means it’s night-time use only. And it also only works if a light is pointed at it from or very near the driver’s own line of sight – in other words, the car’s own headlights. It won’t work under streetlights or other light sources. Which is why it’s called retro-reflective!

Retro-reflective is thus just about useless from the sides (until you are directly ahead of the car headlights which is too late anyway). Neither is it much better from behind and ahead when you’re in traffic where everyone is driving on dipped lights – Sam Browne, H belts and the like are too high up, and so only show up clearly on main beam. This is one big plus for the Aerostich Roadcrafter I own – it has big reflective panels on the back of the calves for this reason very reason, just as cyclists and kids often wear reflective ankle bands – but I’ve only ever seen one rider wearing them regularly – too “unfashionable”?

So what about daytime riding lights? On most bikes, DRLs are just a normal dipped headlight. Now, it seems to have escaped attention that the functions of a daytime light (to be seen) and a nighttime light (to see with), are almost completely mutually exclusive.

The problem here is that the well designed dip beam reflectors that are so effective at keeping stray light out of on-coming drivers eyes at night, do a similarly effective job by day – all the driver looking at the bike is likely to see is a slightly lighter patch on the front of the bike.

So, particularly when the viewing driver is offset, in other words in the classic SMIDSY position, it’s only if you run on main beam or have a badly adjusted light, or just possibly when they are close enough for the assymetric dip beam on the left to have an effect, will they actually get any light shining directly at them.

So some riders have taken to running on main beam. And then the side effect is that the light obscures the bike behind it, breaking up the outline and effectively camouflaging the bike and rider, making it difficult to judge speed and distance from the observer. And I’m not even going to go down the  route of asking if there is an involuntary ‘flash’ to drivers when you hit a bump or the brakes.

Almost forgotten is that the Transport and Road Research Laboratory investigated DRLs back in the ’70s and decided what was needed was a lower powered (so non-dazzling) but non-directional light. The pattern required was that of a reversing light – so from the mid 70s through till the mid 80s most police bikes had a reversing light bolted to the fairing.

And even when you do use lights, you only add to the “light clutter” that surrounds you; other bikes using DRLs, buses, cars too, shop fronts, illuminated bollards and street signs, streetlights as the elevation changes, security lights and all the rest. How is your headlight going to jump out and say “watch ME” in the midst of all that?

I have no doubt that in certain circumstances the solid outline of black bike and black suited/helmeted rider shows up better than the camouflage effect of panels and blocks of different colours and lights.

Putting all this aside, what effect do DRLs and hi-vis clothing have on drivers looking at you, and how does it make you safer at junctions from the much-feared SMIDSY accident? Why should it be a matter of so much importance that you are seen?

Well, it will only be an issue if you don’t take precautions in case the car pulls out! If you think about it, a hi-vis vest or running with the lights on in daytime is very like ABS. It just might protect you from the consequences of your own error in failing to spot the accident developing in front of you.

ABS cuts in when you’ve braked too hard – maybe you haven’t seen the car in front of you stopping or you haven’t anticipated a slippery surface, or you simply aren’t skilled at using brakes effectively. Whatever, a good driver very seldom needs it.

A hi-vis vest and DRLs are the same – they just MIGHT cause a driver to think twice about pulling out on you in a situation where YOU haven’t anticipated that it might happen, and are unable to take other avoiding action.

But it’s argued that as riders are fallible, and so hi-vis/DRLs will protect them from the consequences of their mistakes.

  1. IF you can be seen.

  2. IF the driver looks.

  3. IF the driver sees you.

  4. IF he makes all the correct decisions.

Way too many “ifs” for me. So perhaps they don’t see me, despite all my hi-vis aids? Is that a situation I want to get into? Nope. I don’t want to rely on someone else for my safety.

If I am sufficiently on the ball, it shouldn’t matter whether the driver sees me or not – I’ll do everything I need to avoid getting tangled up in HIS accident – there is absolutely NO reason I should have the accident too.

For years I rode with DRLs on and wearing hi vis… and then discussions got me thinking about whether it really works – as well as the solid practical evidence whilst out training with three bikes and riders all wearing hi vis and with headlights on attracted dodgy manoeuvres like cows attract flies.

In all the years I’ve been riding, I’ve NEVER had so many near misses as when I was out with the trainees on basic training courses, and it was clear that drivers were certainly NOT having trouble seeing the bikes, but in fact were deliberately pulling out in front of the group, because “it’s only some learner riders.”

So two years ago [when the article was originally written], when riding for myself the lights went off. The hi-vis went on the hanger. Any difference? None that I can notice!

I suspect it’s partly that I don’t approach junctions as quickly and in such poor positions as some riders, as I think about things like the other driver’s line of view and the time they have to see me – and my own stopping distances. I do things like time my approach to a junction so that there’s something going past from the opposite direction at the same time, or open or close the gap ahead of me as appropriate to encourage or discourage a driver from turning, avoiding “should I, shouldn’t I” hesitancy. I move laterally across the road to attract attention in peripheral view.

If you do the right things – change position, slow down, cover the brakes, accelerate in a responsive gear once committed, the “killing zone” in which there is no way of escaping the emerging car by stopping, swerving or accelerating isn’t very big. Even if the car does a brick wall impersonation, from 30mph you can stop in 3-4 bike lengths if you are the least bit good on the brakes. Walk that distance backwards from the centre line of a side road (on the pavement preferably) and see what that means in terms of how LATE you can brake and still stop.

Being objective about it, hi-vis/DRLs are only of any use if I fail to make sufficient adjustments, either through ignorance, choice, or cock up. So if I take responsibility in situations where there is a potential conflict in such a way that I negate (or at least, massively reduce) any chance of an accident, then what REAL use are hi-vis/DRLs other than to make the rider FEEL safer?

It’s hard to find any flaw in that argument.

The case for hi-vis isn’t really supported by the evidence. There was a much reported article in the British Journal of Medicine in 2004 which claimed a link between safer riders and use of hi-vis. Unfortunately, the analysis of the evidence stopped short of revealing the real answers. The riders who had the accidents were:

  1. under the influence of alcohol

  2. driving whilst disqualified or without a licence

  3. inexperienced

  4. riding new (to them) machines

In other words, it was less to do with dressing like Dayglo Derek and more to do with skills and attitude. All stuff which has been known about for 40 years.

You would also have expected to see drops in accident rates in general over the last couple of decades as riders increasingly lit up and dressed up, and there should be another “blip” about now as permanent wired-on lights take effect. There’s certainly nothing immediately evident in reduced accident statistics, and no study to my knowledge has claimed to have found such an effect.

Whatever,  in my opinion, much of the endless debate about the pros and cons of DRLs and hi-vis is futile – a rider would be wiser to concentrate on working out where and why accidents happen in the first place, and in the second, working on the techniques and developing skills to avoid becoming one.

Now,so long as we understand that, there’s no real problem in stacking the odds a little further in our favour because we do make mistakes. In conditions of poor visibility, then I WILL don something to help me be seen. Fog and spray are the worst so on goes the hi-vis kit.

Nitrondo a very nice jacket that they supply to the police and paramedics, made of waterproof flexothane too, that’ll no doubt last a couple of years. It’s a bargain at £129.99.

However, it’s worth pointing out that’s only a little less than one day course with Survival Skills, or any of the other training courses! And the knowledge from those will last a lifetime.

A jacket for a couple of years? Or skills for life?

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