The truth behind Hi-Viz

As we all know, High Visibility clothing is seen as a must have safety item for cyclists. With the biggest selling items being jackets and rucksack covers.

High visibility clothing or fabric is made up of a fabric which is bright in colour and often has fluorescent properties, in addition there are reflective strips. The fluorescent properties of the material only work in natural light and the reflective strips only work if a light source is shining on it.

Fluorescent clothing works best during hours of natural light because the clothing ‘converts’ ultra-violet light into visible wavelengths, which makes it appear brighter than other colours and objects. It’s noted that it stands out considerably during poor conditions, such as rain and fog. Light from non-natural sources doesn’t contain much ultra-violet and thus the fluorescent properties of the clothing provide no advantage against non fluorescent clothes.

In most cases, the reflective panels on hi-viz clothing are designed to reflect light back at the source, in a handful of cases the reflective panels reflect light in all directions, this usually weakens the appearance of the reflected light. The more common type of reflective material (known as retro-reflective), reflects light at only a few degrees. So the performance of a reflector can appear very different from the perspective of a lorry driver vs a car driver. As the observation angle increases, the performance of the reflector drops.

So hi-viz is made up of two parts, one being good for day time visibility and one being good for night-time visibility. But they have their drawbacks. With growing numbers for road users being seen wearing fluorescent clothing it can have the effect of making you blend in with others and thus not standing out from the crowd, not the effect you always want. The retro-reflective material only reflects light back at the observer if they shine light at it.

The limits to retro-reflective material can be seen quiet clearly in the pictures below. Due to car headlights shining no higher than the waist of the average person. Any retro-reflective material won’t shine back a strong light because there isn’t much shining on it. In one of the pictures I lower the hi-viz cover into the headlights of the car and quiet clearly there is a difference between the two.

High visibility clothing is obviously great for standing out. After all that is what it is designed for. Cyclists in a busy city have to weigh up the options. At night the Hi-viz jackets and rucksack covers are next to useless unless you have rolling hills. During the day they can help you stand out but if you get into a group of other cyclists you may blend in, which can result in someone miss-reading your speed.

During the day I think it is personal choice about wearing hi-viz jackets, I personally don’t, I would much rather turn my lights on than wear yellow.
During hours of darkness I don’t see the point in wearing hi-viz jackets, it adds limited visibility. You would be much better off wearing retro-reflective on the legs and feet. Not only are these in the headlight zone of a motorised vehicle but they also move as you pedal. Adding in a much more attention grabbing effect.

Walking with cleats

Many cyclists say that a downside to a road cleat system (e.g. Look Keo) is that they are hard to walk in. But are they really?

Sometimes people look for the worst in products to make excuses not to buy them. Road cleat systems are the perfect example. They have many benefits including a secure grip for putting down the power and bigger platforms for comfort. Unfortunately many people are put off by the fact that some people find them hard to walk in.

I personally have no issue walking in them, it’s the same as any normal shoe. In fact each day i walk through gravel, up 10 flights of stairs and across a marble floor without issues. In each case I walk like a normal person but my shoes make a different sound.

They may not be the best cleat to go walking around the supermarket in doing your shopping or walking several miles in but I have done both of those several times without issues. If you plan to do walking or shopping etc. Then using MTB cleats with a shoe that uses a recessed cleat is definitely the way forward.

I will admit that I have one problem with them. And that’s walking down stairs, size 12 feet + cleated shoes + stairs = a nightmare!

Hi-Viz, the new helmet debate.

Hi-Visibility clothing is designed to make you stand out. The bright flourescent colours absorb UV light and output it in a light form that is visible to us. Hence why during the day, they stand out but at night, it’s a different story.

With every Tom, Dick and Harry wearing Hi-Viz on a bicycle, does it actually make you stand out?

When cyclists talk about hi-viz, we normally refer to yellow jackets. These things are normally too heavy and thick for day use, which the hi-viz is designed to work in. Reflective strips of tape make you stand out in the dark. Are these jackets actually effective at making you visible or is hi-viz the new helmet debate?

A recent study in Australia shows us which one is true.
The study was conducted on a closed road circuit at night where driver participants of various ages were in a specially equipped vehicle and bike rider participants wore various combinations of clothing.
Due to hi-viz working off UV radiation, the hi-viz is useless at night due street lighting and headlights not producing UV radiation. The results showed that flourescent colors did not provide a significant improvement on black clothing at night.

Due to many cyclists thinking that Hi-viz makes them stand out at night, they could be putting them selves at risk if their clothing doesn’t contain reflective material.

Even when the cyclists wore a reflective vest, the drivers said it wasn’t as clear as reflective 3M scotchlite tape on their ankles and knees. This is thought to be down to the torso of a cyclist mostly being still and the ankles and knees are more often than not moving.

Whilst there aren’t many studies out there about Hi-Viz and its apparent safety features for cyclists, I don’t think the study in Australia is one to be sniffed at. It certainly makes more sense that reflective tape on a cyclists ankles will be more attention grabbing in car head lights rather than a vest which won’t get as much light.

I’m not a fan of the Altura NightVision jackets and similar jackets because during the day they are too thick for wearing and at night the reflective tape is often covered by a bag.
And as the study shows, the opinion from drivers, is the hi-viz doesn’t work at night and reflective tape is much better situated on the leg where it is moving more than the torso.

ProViz came up with the idea of using a strip of lights on their jackets and bag covers to make yourself more visible. I’ve yet to see one of these in the real world so I can’t comment on how well they work.
Some cyclists over at CycleChat have been talking about self illumination to make your self morevisible, that is pointing an LED light at yourself rather than the other way. To clear results have yet been seen but it can’t hurt trying.

My personal feeling on hi-viz is just go with out. With over 70% of cyclists wearing it, you really don’t stand out whilst you’re in it. I would much prefer to spend the money saved on Hi-Viz on some reflective tape and a good set of lights for my bike. I use my lights during the day to make up for the lack of hi-viz.