Conspicuity for cyclist survival
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CONSPICUITY FOR CYCLIST SURVIVAL. Jack Holmgren Member San Francisco Randonneurs Randonneurs USA 3-31-12 (All errors and opinions are the author’s). Don Mitchell at the start of the 2009 Gold Rush Randonnee. Our Fallen Comrades. Bruce Taylor – 2010 Don Mitchell – 2010

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Conspicuity for cyclist survival


Jack Holmgren


San Francisco Randonneurs

Randonneurs USA


(All errors and opinions are the author’s)

Our fallen comrades
Our Fallen Comrades

  • Bruce Taylor – 2010

  • Don Mitchell – 2010

  • Jim Swarzman – 2011

  • Others hurt or killed by cars at night, in low-light, or daylight

  • We owe it to them to be as conspicuous as possible.

The problem drivers
The Problem = Drivers

  • The man who struck Don Mitchell at 50 MPH

  • 78 years of age

  • Driving near on-coming traffic – glare

  • Twilight

  • Shortly after the switch to Daylight Savings

  • Was likely 4 feet into the shoulder

  • Credibly said that he NEVER SAW Don

Holmgren s first law of cycling survival
Holmgren’s First Law of Cycling Survival

  • You can never be too conspicuous.

Cars and bikes
Cars and Bikes

  • Drivers – Younger AND Older Fail to compensate

  • Limitations at night

  • Reduced contrast

  • Sensitivity to glare

  • All of which decrease their ability to SEE CYCLISTS.

We know drivers fail to compensate
We know Drivers fail to compensate

  • Is this bad?

  • Yes, it is bad.

  • But what can we do about it TODAY?

  • We can compensate for the drivers by being MUCH MORE conspicuous.


  • The property of being clearly discernible.

  • The state or quality of being clear or bright; brightness; conspicuousness.

Vis quiz the best way to boost awareness of a cyclist in the dark low light is
Vis Quiz – The best way to boost awareness of a cyclist in the dark/low light is:

  • 1. Blinking tail light ____

  • 2. Solid tail light ____

  • 3. Reflective vest ____

  • 4. Reflective Sam Browne Belt ____

  • 5. Rear facing horn ____

  • 6. Reflective ankle bands ____

  • 7. Reflective material on cranks ____

Biological motion biomotion
Biological Motion (Biomotion) the dark/low light is

  • Drivers see and recognize a human form:

  • Retroreflective material

  • Worn on moving Joints

Survival conspicuity material
Survival Conspicuity - Material the dark/low light is

  • Start with the shiny stuff as it works in the rain/fog/sleet – buy products made with slick retroreflective material - see article in American Randonneur, Reflections on Retroreflectivity

  • Go for as much as you possibly can get.

  • Beware of phrases like “reflective accents.”

Survival conspicuity biomotion is the most important
Survival Conspicuity - Biomotion is the Most Important the dark/low light is

  • Ankle, ankle, ankle

  • That’s about the only place on a cyclist that

  • Brings out the biomotion.

  • Rivendell makes big, fat, slick ankle bands.

  • They cover the leg and stick out a few inches.


  • You want the “best and the brightest.”

Survival conspicuity reflective clothing
Survival Conspicuity – Reflective Clothing the dark/low light is

  • Calculate coverage – how many square inches/centimeters of reflective material?

  • Look only to the reflective coverage, e.g., some ankle bands have bright colored fabric and only .5 or .75 inches of reflective stripe.

  • Reflective material that is 90 degrees to the road or close to that is most reflective.

  • Think about the garment’s angle to vehicle headlights as worn by the cyclist while riding.

Moonbeam DIY modification – 4 inch wide strip of slick material sewn to the bottom of the back of visibility vest

Survival conspicuity camelbak issue
Survival Conspicuity – Camelbak Issue material sewn to the bottom of the back of visibility vest

  • Put

  • Your

  • Camelbak

  • On

  • Before

  • Your


Viz quiz the best way to boost awareness of a cyclist in broad daylight is
Viz Quiz – the best way to boost awareness of a cyclist in broad daylight is:

  • 1. Rear facing horn___

  • 2. “Share the Road” decal on top tube___

  • 3. Clothing that uses black and colors found in nature like brown, green, eggplant, blue…___

  • 4. Clothing that uses retroreflective material___

  • 5. Clothing that uses loud colors like Hi-Viz Yellow, Safety Orange___

  • 6.Mixed in checks or chevrons___

Is this conspicuous
Is this conspicuous? broad daylight is:

  • Go to the Rapha, Capo, Castelli, Pearl Izumi, You-Pretty-Much-Name-It cycling clothing company website and click on all the “cool” looking black and earth-tones clothing.

  • In their defense, they are responding to a degree to market-share pressure. Be the pressure and don’t buy these drab and invisible colors and they will go away.

Traffic master jersey a good example http www elevengear us trafficmaster html
Traffic Master Jersey – A good example broad daylight is:

Survival conspicuity wear clothes that stick out during the vast majority of your riding daylight
Survival Conspicuity – Wear clothes that stick out during the vast majority of your riding (Daylight)

  • Contrasting colors are best

  • Hi-Viz Yellow

  • Safety Orange

  • The two winners (In a 1994 study, “...fluorescent yellow was found to be best detected and fluorescent orange was found to be best recognized against any of the three backgrounds investigated.” (Zwahlen & Vel, abstract) )

  • But these are of little help at night/low-light.

  • Don’t get lulled into thinking you’re safer just by wearing these colors at night.

Survival conspicuity distractions competition for driver attention
Survival Conspicuity – Distractions = Competition for Driver Attention

  • GPS

  • Cell Phone and Audio

  • Cars and Buses

  • Signs and Scenery

  • Pedestrians and animals

  • Threat level highest in urban environments so APPLY Survival Conspicuity to your COMMUTE

Survival conspicuity fashion quiz
Survival Conspicuity – Fashion Quiz Driver Attention

  • Would you rather:

  • 1. Look good on the bike and be hurt/dead?___

  • 2. Look like a clown on the bike and be alive?___

  • If you selected #2 then consider wearing your L2s visibility vest always (that means on your commute, brevets, permanents, centuries, double centuries, training rides, etc.).

  • Clubs can order custom L2s vests at:

Survival conspicuity tail lights
Survival Conspicuity – Tail Lights Driver Attention

  • Which is more important?

  • Your fellow riders not liking your bright lights?

  • Getting killed/hurt by a car because you did not have the brightest lights?

  • Always move up with the technology, e.g., Planet Bike Super Flash .5 Watt was the best but PB Turbo Flash = 1 Watt can and should be used in daylight too.

Survival conspicuity to flash or not to flash
Survival Conspicuity – To flash or not to flash? Driver Attention

  • Randonneurs must have A steady light in low-light and at night.

  • Some run that and one or several flashing.

  • Flash or steady is personal.

  • The point is to have good LIGHTS (plural)

  • Multiple lights are part of the Rando ethos of back-up.

Survival conspicuity multiple tail lights
Survival Conspicuity – Multiple Tail Lights Driver Attention

  • “Volagi” mount (brake bridge)

  • Seat-stay mount

  • Helmet mount

  • Many is much better than one

  • Is this obnoxious?

  • Yes.

  • Does it make you more conspicuous?

  • Yes, and that is more important than anything.

Survival conspicuity aim
Survival Conspicuity - Aim Driver Attention

  • Not about alerting Martians

  • Aim for the Earthlings

  • No seat-bag, seat-pack, Carradice bag, pannier, Camelbak, mounting of lights as too much variation

  • Have a friend help by looking at the light from several distances, e.g., 50, 100, 200, 300, 500 meters to determine optimal positioning.

Survival conspicuity always ride with lights on
Survival Conspicuity – Always Ride with lights on Driver Attention

  • Cars turn their lights on during the day.

  • So can you! Increases conspicuity by day

  • Many lights designed to be seen by day:

  • Planet Bike Turbo Flash

  • Portland Design Works Radbot

  • Dinotte

Survival conspicuity front lights
Survival Conspicuity – Front Lights Driver Attention

  • Have good ones.

  • Have a back-up.

  • Daytime running lights – an idea whose time has come.

  • Endorsed by Robert Choi, inventor of the LED tail light!

Survival conspicuity reflective bikes and bits
Survival Conspicuity – Reflective bikes and bits Driver Attention

  • Powder coated reflective paint rims and frames

  • Stick-on bits of reflector on cranks, seat stays, helmets (up high so they’re visible in areas with many cars), etc.

  • Strands of bendable lights to wrap the frame with.

  • Reflective strips on tires and spoke lights.

  • Lights that project the image of a bike lane.

  • All communicate that the driver is approaching a cyclist.

Survival conspicuity organize
Survival Conspicuity – Organize! Driver Attention

  • Join a/several bike coalitions:







Survival conspicuity organize1
Survival Conspicuity – Organize! Driver Attention

  • Amplify your voice with a chorus by joining a coalition or several coalitions.

  • Support programs that lead to greater driver cognition and awareness of cyclists in daylight, at night, and in low-light.

  • Ride with others in low-light or at night.

  • Ride with others in daylight.

Daytime riding
Daytime Riding Driver Attention

  • Helmet + Ankle Bands + Conspicuity Vest + Daytime Strength Tail Lights +Daytime Strength Front Light =

  • SAFETY or greater safety

Night time riding
Night Time Riding Driver Attention

  • Helmet + Ankle Bands + Conspicuity Vest + Daytime Strength Tail Lights + Night Time Strength Front Light (s) =

  • SAFETY or greater safety

A n c l
A-N-C-L Driver Attention

  • A = Ankle bands for biomotion

  • N = Noggin for helmet to protect same

  • C = Conspicuity Vest for conspicuity

  • L = Lights for front and back always on even by day

  • Do an ANCL check just before riding off.

Holmgren s second law of cycling survival
Holmgren’s Second Law of Cycling Survival Driver Attention

  • You should always try to be more conspicuous!

Thanks Driver Attention

  • To the science gals and guys at Queensland U out there in Brisbane, Australia.

  • FEMA

  • They study this stuff and publish so that I can lift much of it verbatim and put it on the screen.

  • Thanks to them and thanks to all the researchers working on this life and death issue.