Emergency workers and HiVis clothing – our perception of safety may be dangerously flawed!

Just how how safe are we as emergency workers at an incident scene when stepping out onto the road ? Our on-road activities are an integral part of life in an ambulance/EMS, police, fire or rescue response. We pull-on a ‘safety’ vest or fluorescent jacket over our uniforms and then start work, trusting our lives to the passive conspicuity built into a piece of clothing that is specially designed and officially sanctioned  for use day & night in hazardous situations.

Over the years there has been a vast amount of detailed research undertaken, along with changing OH&S legislation and recent occupational education, all reinforcing that emergency workers can substantially increase their on-road ‘safety’ margin by wearing a fluorescent/reflective vest. Regardless, emergency workers should always concentrate on maintaining a high level of situational awareness at incidents and never, ever turn their back on traffic. As a group, all workers have been repeatedly reassured that protective clothing continuously radiates a spectrum of colour enhanced conspicuity through 360 degrees. I too have been guilty of always believing in this dictum (albeit somewhat nervously and with occasional reservations) but after reading a recent email sent by Malcolm Palmer, I am not so sure anymore!

Malcolm works with the Transport Research Laboratory (TRL) which supports facilities located all around Great Britain. In 2009/10 Malcolm and colleague Shaun Helman researched a comprehensive report at the request of the UK Highways Agency. The Road Worker Conspicuity Report (Daytime & Night-time)  examined the following issues:

1. The perceptions of road workers and personal opinions of their own conspicuity.                                                                                                                                        2. The distances at which road workers are seen by drivers on a naturalistic but controlled test track.                                                                                                                                                            3. Visibility ratings for different types of PPE.                                                                                 4. Differences between the subjective ratings of visibility for coloured PPE materials against different background (vehicle) colours.                                                                               5. Driver expectations; what is the likelihood of encountering road workers in the proximity of stopped vehicles displaying warning lights?TRL Roadworker Conspicuity Report

This research project was different: – Unlike most earlier studies, the test participants were not given specific instructions to search for the key visual elements. The test participants provided a running commentary as they drove around the track and were interviewed later after the drive. The research results demonstrated that unlike earlier research, road workers were often detected only at short distances, sometimes as low as 25 to 45 meters (27-49 yards).  The road workers were also found to be less than conspicuous, even when wearing high-visibility clothing.  The workers that were interviewed for the study were also likely to greatly over-estimate their personal levels of conspicuity.

Even more surprising was the fact that greater than 50% of the test-driver participants in their everyday driving (off the test track) did not expect to see people around a vehicle when its warning lights were activated! This amazing outcome very much flies in the face of most common beliefs.

The report found there was no major difference between the differing colours of PPE when detection distances were considered, although under road lighting at night, orange PPE against a white vehicle  had a slight advantage in detection. Also the headlight patterns on new vehicles tend to display a low and very marked light cut-off height. Subsequently the authors recommended that road workers affix retro-reflective material below their knee-height or preferably around ankle level on work trousers. Using flourescent yellow trousers or over-pants during daytime increases the surface area of the safety colour thus increasing conspicuity.

Vehicle & protective clothing blending

Protective clothing blending with an emergency vehicle in Battenburg markings

Finally, the study indicated that organisations should consider using white coloured vehicles as they are easier to see at night. Care should be exercised however as there is also a possibility that the use of yellow PPE alongside white vehicles in daylight conditions might lead to ‘blending’ or ‘camouflage’ issues between the two colours. The operating landscape of both vehicles and staff should be considered carefully when choosing vehicle colours, markings and protective clothing.

Reading this important study has certainly changed my perceptions about my conspicuity and it is definitely a report that will change common assumptions in others about their own personal safety. This report document should be widely circulated to your colleagues, around your local stations and throughout your agency’s administration.

Read the Road Worker Conspicuity Report by Helman and Palmer                                      Also read a preceding TRL report by Chattingham, Langham & Rillie                                         High-Conspicuity Garments for Roadworkers

More research is available from the Ambulance Visibility Reference Library or by viewing the Ambulance Visibility website. Comments on this post are welcomed!


About John Killeen (Ambulance Visibility)

John Killeen is a former Intensive Care Paramedic who authors the Ambulance Visibility research website & blog
This entry was posted in Ambulance, AV Reference Library, Battenburg, Emergency vehicles, EMS, Fire, Fluorescent colours, High Visibility, Police, PPE, Reflective, Rescue, Research, SES, Significant & Important Blogs and tagged , , , , , , , , , , , , , , , , , , , . Bookmark the permalink.

3 Responses to Emergency workers and HiVis clothing – our perception of safety may be dangerously flawed!

  1. Tammy says:

    Great read John. There has been a lot of discussion here in Aus re Hi Vis and how effective it is. Personally I think it’s the complacency of both the wearer and the road user that is the problem and therefore making it less effective. Would you agree? Tammy


  2. Colm Moore says:

    Possible additional issue.

    Mixing hi-vis colours, like in the outfit on the left here: https://ambulancevisibilityblog.files.wordpress.com/2012/03/ppe-report.jpg means that the human shape is lost.


    • Colm, thanks for your comment. A slight loss of shape may well occur in daylight due to the two fluorescent colours but the advantage of being seen in some climates against changing operational and seasonal backgrounds is a distinct advantage. There was also the issue of identifying paramedics in a “sea of green” emergency responders from several different agencies working at an incident. The major design issue to be overcome is successfully balancing the use of two fluorescent colours in close proximity to each other.


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