High-vis on cyclists unlikely to stop dangerous overtaking

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High-visibility vests, often handed out by the Gardai and schools, are unlikely to help cyclists from the most dangerous overtaking according to researchers.

The conclusions came from a study using an ultrasonic distance sensor attached to a bicycle used on a daily commute.

The average gap which a motorist left while overtaking the cyclist was recorded at 1.18 meters, a decrease of more than half a meter from a study at the end of the 70s when the average gap was 1.79 meters.

Today’s average is notable shy of the 1.5 meter minimum passing distance recommended by safety bodies, including the Road Safety Authority.

Researchers at University of Bath and Brunel University have just published their findings in ‘Accident Analysis and Prevention’, a peer-reviewed public health journal.

Wearing one of seven outfits at random on his commute in London over several months, Dr Ian Garrard from Brunel University, used the same bicycle and always cycled in the same way.

The study included Garrard wearing seven outfits at random – a number of types of high-visibility jackets and vests, a plain cycling jersey with plain trousers, a rugby shirt with a small rucksack, and a colourful skin-tight Tour de France cycling jersey.

The researchers expected different appearances would signify the cyclist’s experience level.

One of the high-vis vests warned “novice cyclist”, but researchers found that the amount of space left by motorists as they overtook a bicycle was not related to the outfit worn.

The authors say: “The only substantial change in drivers’ behaviour was seen in response to a high-visibility vest which invoked the name of the police and suggested the rider was video-recording the journey, although at present it is not clear which of these components was responsible for the effect.”

Cyclist.ie claims close overtaking “magnified” by narrow bus lanes common in Ireland.

But not even the ‘police’ high-vis vest deterred a small proportion of overtaking drivers from passing within 50cm of the rider. The 1-2% of motorists who came this close did so “no matter what was being worn”.

Given this result, the authors conclude: “There is little riders can do, by altering their appearance, to prevent the very closest overtakes. We suggest that the optimum solution to the very closest overtakes will not lie with bicyclists them selves, and instead we should look to changes in infrastructure, education or the law to prevent drivers getting dangerously close when overtaking bicyclists.

Brian Farrell, spokesman Road Safety Authority, said that the agency’s research department would need to study the research in more detail to provide a full and considered response.

“This problem of inappropriate clearance distance from cyclists when overtaking is something that needs to be tackled though education and that’s why we have dealt with it directly in our TV advert which aims to show drivers how they should interact with cyclists. I can also confirm that this ad will be back on TV screens in January and throughout 2014,” said Farrell.

Lead researcher Dr Ian Walker from the Department of Psychology at University of Bath told this publication that “at some point you have to question the utility of high-vis”.

Walker said: “I’d note that there is a surprisingly substantial body of research which suggests there’s no real benefit to wearing it. For example, a recent case-control study found no difference in accident likelihood between users and non-users. So it doesn’t seem to reduce accidents, and [their research shows] it doesn’t seem to stop drivers getting close.”

Mike McKillen of Cyclist.ie says that the research confirms his “experience of 42 years” and that he thinks the level of close overtaking is “magnified” on Ireland’s often narrow bus lanes where buses, coaches and taxis regularly attempt to overtake cyclists too closely.

MORE: Download the research in full

MORE: RSA overtaking cyclists video:

OUTFITS USED IN STUDY (also pictured above):

COMMUTE: Plain cycling jersey, plain trousers, reflective cycle clips, Bell commuting cycle helmet, cycle gloves.

CASUAL: Rugby shirt, plain trousers tucked into socks, woollen hat or baseball cap, plain gloves, small rucksack.

HI-VIZ: Bright yellow reflective cycle commuting jacket, plain trousers, reflective cycle clips, Bell commuting cycle helmet, cycle gloves.

RACER: Colourful, skin-tight, Tour de France cycle jersey with sponsor logos, Lycra cycle shorts or tights, sleek race-fitting cycle helmet, cycle gloves.

NOVICE: Yellow reflective vest with words “Novice Cyclist, Pass Slowly”, plain trousers, reflective cycle clips, Bell commuting cycle helmet, cycle gloves.

POLICE: Yellow reflective vest with words “POLICEwitness.com – Move Over – Camera Cyclist”, plain trousers, reflective cycle clips, Bell commuting cycle helmet, cycle gloves.

POLITE: Yellow reflective vest with blue and white checked banding and the words
“POLITE notice, Pass Slowly” looking similar to a police jacket, plain trousers, reflective cycle clips, Bell commuting cycle helmet, cycle gloves.


  1. This is unfortunately true on our roads,motorists passing within a few inches of Cyclists. I have often been cycling along pleasantly and all of a sudden you feel the sensation of a large force pushing passed and you turn around and get the shock of your life as a Bus goes pass your fingers at a fast speed at a distance of 4 inches away from you.

    This keeps getting repeated every day of the week anywhere in Dublin whether it is broad daylight or night time. I have seen Buses doing this to loads of Cyclists on the Nth Strand Road,not just one Cyclist but continuously for over a km.Taxis are another problem too at speeding by Cyclists .

  2. I agree that wearing hi vis while cycling in Dublin makes little difference to the space motorists give you when overtaking. I have also tried various combinations of clothing while commuting by bicycle and have found that the only thing that works for motorists to notice you is a short skirt and no hi vis. Unfortunately not so practical at this time of year but I definitely feel safer when I look less like a cyclist.

  3. A great bit of research by Ian Walker and some surprising results. Two variables that weren’t covered in the paper were the road width and the light levels. It would be interesting to know if there were more near hits on narrow roads or in dark or overcast conditions.
    As a regular cycling commuter and occasional motorist, I am a strong believer in having good lights and a hi-viz jacket even if it adds to the “dangerisation” of cycling. Anything that makes me more visible to a driver half blinded by oncoming lights makes sense to me.

  4. Part of the solution is for cyclists to use defensive road positioning. That means dominating your road space, and maintaining an “escape space” between you and the edge of the road, from 1 to 1.5 metres. So, if you are in the unfortunate position of having a driver try to overtake you with too little clearance you have a safe place to steer into to avoid their foolishness. The one accident I have had in recent years was when I failed to use this tactic — a driver brushed past very close on a narrow road, where I was cycling too close to the kerb. Because I had no safety zone, I ended up taking a spill and injured a knee in the process. I find that I rarely have a problem when I do maintain a safety zone and assert my right to my position on the road.
    I have also found that high-vis clothing makes no difference whatsoever — the way I have been treated by drivers has depended primarily on my own actions as a cyclist and my positioning on the road.
    Also, as a last resort, many cyclists now use small cameras to record their rides — especially with two cameras, one facing to the front, and one to the rear. These can prove to be invaluable in establishing responsibility in the event of an accident.

  5. Danish research involving 6.800 cyclist found, that cyclist wearing a high-vis jacket had 48 % fewer accidents. Here is the abstract for “The safety impact of a yellow bicycle jacket” (forthcoming in Safety Science):

    The hypothesis of this project is that the safety of cyclists can be improved by increasing their visibility in traffic. This is explored by testing whether or not a high-visibility bicycle jacket (colour and reflectors) will increase the safety of cyclists. The project has been carried out as a randomized controlled trial with 6,800 volunteer cyclists. After random selection, half of the group – the test group – got the bicycle jacket at once and promised to wear it each time they biked during a year. The other half of the group composed a control group that got the bicycle jacket after the closing of the project, i.e. after a year. The safety effect of the bicycle jacket was analysed by comparing the number of self-reported accident for the test and control group. The self-reported accidents showed that the test group had 38 % fewer personal injury accidents with other road users – so-called multi-party accidents – than the group who did not wear the bicycle jack-et. If one only looks at accidents between participants and vehicles, the difference is 48 %. The differences are statistically significant at 5 % level. In the test group, 37 % of the involved parties in an accident report-ed that they were not wearing the bicycle jacket or any other bright-coloured garment when the accident occurred. http://vbn.aau.dk/da/publications/the-safety-impact-of-a-yellow-bicycle-jacket(6ef90648-d4b4-4ad0-940e-360ce1436721).html

    The Danish report can be found here: http://www.e-pages.dk/trygfonden/239/


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