Yes, You/We ARE Invisible!! Part1

[TopCatGr58]

Hey there Xsives,

I've been planning this post/tech tip for some time, but in lieu of recent posts about riders going down/getting turned in front of, etc., seems like a timely opportunity for it! There is a lot of data that is being presented in this, I tried to put it into formats that are easy to understand and relate to!

I'm a Certified Ophthalmic Technician/Surgical Assistant with over 25 years of experience. I am at times required to fill out patient's DMV forms stating their visual function levels, so I am very familiar with the standards!

Most everybody knows that 20/20 vision is the accepted level for normal good vision, but what you may NOT know is that you are NOT required to have 20/20 vision to DRIVE! The standards of vision in Best Corrected/wearing glasses values for driving across the USA are as follows:

20/40 vision and a peripheral field of vision of 100 degrees to have the ability to drive at NIGHT.

20/70 vision and a peripheral field of vision of 70 degrees to be allowed to drive in the DAYTIME.

Now the kicker...this is ONLY ONE EYE!! A person does not need to even have a second eye!!

Commercial/CDL licenses DO require 20/40 best corrected in BOTH EYES, and 100 degrees of peripheral vision.

Some examples. A healthy person's field of vision is appx. 180 degrees, from left ear to right ear when looking straight ahead.
Below is a view taken at a local intersection just standing in the driving lane. Apologies for quality, I don't have a PANARAMIC camera, so there are defects in the Splicing, but you can get the IDEA!

Now from INSIDE the Car:

Now just showing the view to the left from the car, note the TREES, Signal Light Pole, Power Line Poles, etc.!!


Here's a view pulling up to the crosswalk of the intersection.

Now a zoomed in view, do you see the bike yet? It's on the sidewalk, but a full block away!


Now, just a few examples of comparing the view/size of a standard SUV...my Xterra and my bike! Again, didn't want to have bike sitting wayout in road next to car, so I did some splicing!
First, view at 50 feet away.

Now 100 feet away.

Now 200 feet away.


And below is a shot of my bike below a standard Speed Limit Sign. The size of the lettering for the words Speed Limit are ~4" tall, which is just a bit over the 20/200 size lettering we use for vision exams, and this photo was taken at 200 feet, 5Mp Camera at full resolution, and then when I zoomed in on the actual image, the words Speed Limit were illegible, so looks like my camera doesn't quite have 20/20 vision, but close!
Below image has been reduced in res/size for posting.

Continued in part 2

[TopCatGr58]

Yes, You/We ARE Invisible!! Part2

Cont.

Some more background info:

The visual acuity letter sizes were determined over a 100 years ago, calculated on the density and size of the invidual light receptors(rods and cones) and so 20/20 was found to be about a 1/12th of a degree of visual field. Remember, 180 degrees or a semicircle of vision is what we have looking forward with both eyes. The fields of vision overlap with our two eyes, approx. 45 degrees towards the nose for each eye. This gives us ~90 degrees of both eyes vision. This is what also gives us TRUE 3-D stereo vision/depth perception.

Below is an example of this with vertical red lines marking the 45 degress to either side of center of overlapped vision. But note how much to the side is only seen by 1 eye.

Some more examples of reduced peripheral visions.
View of ~100 degrees of periph. vision.
View of ~70 degrees of periph. vision.

MATH: To determine how big of a "BLUR" area would be according to a person's visual acuity at specific distances. These sizes are NOT totally blind areas, but are the size that an object could be and NOT be discernible or able to tell what it is at these distances.
20/40=1/6th deg; 20/70= 1/3rd deg; 20/200=4/5th deg.

I used basic math.
Circle's circumference= Diam*3.14pi=360degrees
1/2 circumference= 1/2 diam or Radius * 3.14=180 degree
Radius 20ft *12"*3.14=~754" 180 deg
1 degree = 4.18" at 20feet.

This same formula was used for the 50ft, 100ft, 200ft, 500ft distances.

Blur Area Size and Distances

Visual      20feet   100feet   200feet   500feet
Acuity
20/20       0.35in    1.7in     3.36in     8.4in
20/40       0.63in    2.1in     6.3in      15.7in
20/70       1.14in    6.3in     12.6in     31.5in 
20/200      3.25in    16.8in    33.6in     84 in

Other sizes of interest: Not including a fairing!
XS11 with rider appx. 2ft wide x 5ft high = 10 sq. feet area.
Xterra/SUV appx. 5ft wide x 6ft high = 30 sq. feet area.

Most in town residential traffic is 35mph, maybe 45mph for city. A vehicle at that speed covers 50ft a second. A common block length as ~500 feet, or 1/10th a mile, and will be travelled in 10 seconds, quicker if faster of course!

Now a few shots at the very edge of the intersection like someone would do before turning right. The bike again is a FULL BLOCK away...on the sidewalk! Just 10 seconds away at 35mph.

A zoomed in view.


Here it is ONLY 1/2 block away, a mere 5 seconds away at 35mph.

And a zoomed in view.


So, now looking back at the blur sizes for certain visions at certain distances...a person with 20/20 could have trouble seeing something that is ~8.4" big...the size of your round headlight is 7"! A person with the bare minimum 20/70 vision could not discern an object 31.5" big...remember we are about 24" wide!

Oh...but there's more!! The human eye has a Natural Blind Spot in it. It's where the optic nerve plugs into the eye, all of the millions of fibers span out from this location to map out the eye's vision, but this area itself can not see. It's about 10 degrees wide by 15 degrees high, and just 10 degrees towards the ear from center of each eye. We usually never see it because the other eye's retina sees for it. Here's an example looking straight ahead. Notice how big they are in relation to that TRUCK!

These spots' locations are in reference to the actual photo, not to you sitting here looking at your computer screen. HOWEVER, if you have a 19" monitor at 800x600, are sitting ~20" away, you can cover your right eye and look at the RIGHT dot with your Left eye, and the LEFT red dot will disappear! Vice versa for the other eye. You may have to move inward or outward a little depending on your screen size!!

Our population is aging, their eyesight is failing, their bodies and necks are stiff, so they don't often bother turning their heads very far left or right to check down the road!! And so IF they turn their heads just 30 degrees left, their right eyes 45 degrees of nose side vision will NOT cover the full 80-90 degrees left view down the road, and so their natural BLIND spot can occlude a fairly large area and won't be seen by the right eye, and you can have this situation!


So...in conclusion....it's best to ride as though you ARE invisible.

Be safe out there!

[Brian_D]

TC,

Can I use this as my defense against the next mc speeding ticket?

All joking aside, thanks for the informative post. Excluding the built-in blind spot, are there specific colors (clothing, etc) that are proven to make the motorcyclist become more visible?

[prometheus578]

"Thanks for the tips, T.C."

This might also explain why women have been failing to notice me all these years.
(well, it's as good an excuse as any)

But... a good exercise you did, TC.
We've all had drivers "look right at us", yet continue to pull out in front of us.

And as you state, we are invisible.
Get used to it.

Brian,
Reds can be too dark... Good visability with orange or yellow.

[ClarkGriswald]

Great info, that red dot thing is too fun. Never knew about that.

[CarolynS]

Smith System

I am a graduate of the Smith System of defensive driving. In that program, one thing they try to get across is 'make sure they see you', among 4 other key points of defensive driving.
This means if you have to slow down, flash your lights, or even hit your horn to do so, make SURE they see you.
It gets harder and harder to do so. In this world, people are so self centered(talking on their cell phones, speeding, etc.), lacking in feelings of responsibility(it's not my fault I hit him, the kids were screaming, phone rang, etc.), and just downright ignorant to how things work(my loaded fuel tanker takes more than a football field to stop at 40mph), all any of us can do is try our best to understand these issues and prepare for them.
Great read T.C.! If you know what you're up against, it makes it easier to be as safe as you can possibly be!

[madmax-im]

ThankYou.. TC for confirming what i've known for some time..That we are invisible.Your photos brought it home rather precisely what it is we are up against....thats why you all see me in my nerdy Hi-Viz lime/yellow jackets.Sure leather jackets look alot nicer style wise but I get more protection and visibility in my textile jackets...
TC as a follow up you should do a study to demonstrate what bright riding apparrel and even bright headlamps can do to increase one's visiblity.
Alot has been said positive and negative about Headlamp Modulators...bottom line is they work ppl see them from a ways off...Also bikes should rig running lamps ...LEDs that emit bright White light for the front and sides of the bike and Bright amber/red LEDs for the rear.
I have been saying this for a while now "Loud Colors Save Lives"
As we all know our choices in riding gear are personal ones.Even the lack of any riding gear is a choice to be made.I wont lecture and certainly wouldnt dictate,but alot of my brothers and sisters here do not choose to wear the proper gear and have the proper visibility that goes with it.
Most importantly is to remember that no amount of gear will guarantee your saftey in every situation...but it will hopefully in most situations and also reduce the risk of serious injuries.
Also my brothers and sisters....always ride with the awareness that we are invisible to the cagers...always expect not to be seen and prepare accordingly.

[mason79]

wow!

[Guy_b_g]

I've been keepimg track lately and during the last 3-4 months 5 cars have drifted into my lane to the point that I had to take evasive action, or lay on my horn or both.

4 times the driver was on a cell phone, and one driver was holding the top of her wheel with her hands and texting with her thumbs.

All this while in my cage driving on a 4 lane road to and from work.

2 Other cars failed to notice that the light had gone green at stoplights and they were both on cell phones.

The other day an older gentleman backed into the side of my car as I was backing out of my angled spot in a Walmart parking lot. He said he didn't see me.

We are invisible on bikes, and evidently in cars too these days.

PS great post TC!

[renegade_xs11g]

TC, man that showed me a lot, thanks!

I drive a truck for a living, I have to admit that some things are harder to see than others, some times I think even I am invisible in the big-truck,
and it's 13'6 tall and 102 inches wide with fourteen amber LED's and 4 headlights across the front

daytime running lights help a lot...
those 'ahem' reflective vests help...
some say loud pipes ...........

no, I drive everything like it was Wonder Womans Plane
and it helps the most....

but there will ALWAYS be that 'ahem' person that just don't get it

ALL OF US NEED TO WATCH OUT FOR THEM, no it shouldn't be that way....It's just a fact of life

[xsilerating]

Congratulations, excellent piece, T.C.

An extremely informative, well documented and well presented piece that should be MUST reading for all bikers, cyclists and, motor vehicle operators.

My opinion... you should formalize this in a brochure format and offered (sold) to all Motorcycle Safety Course providers; all student driver training facilities; all DMV offices and, medical eye specialists, eye glass providers, etc. etc. etc. (provided, of course, that all info contained there-in is factual in nature which, I am in no position to question, challenge or, doubt).

It is, without a doubt, a real eye opener (pun intended ).

p.s. I'm in for a return piece of the action .

[TADracer]

Great post, TC

I think most of us either knew or suspected the things you have writtren but it is very, very informative and impacting to see it demonstrated as you have. Plenty of food for thought on how to be more visible in traffic.

Quality of our vision aside, I have always thought of riding as sort of like playing chess (though I am no chess player by any means). You have absolutely no control over what the other guy is going to do so you must plan six moves ahead. And, in traffic you are playing against many more opponents so the gamecan be even more complicated.

[tarzan]

Wow thank you TC! Some times it seems like people AIM to hit us.I tell my friends that people in cars are out to get us.But I know its as you say ,most times the person didnt see.I have had a couple different people try to run me off the road.Once about 15 years ago on a road that was two lane, stop and go, two lane traffic.A guy was tail gating me.I got tired of it so pulled in the next lane to let him pass.Somehow that pissed him off and he raced up swervrd over and slammed on his brakes.I had to lay it down to avoid him.Once in a while someone comes along that I think just hates motorcycles.Anyway I act like they are all out to get me.I dont ride next to cars if I dont have to ,especially in their blindspot.And try to leave plenty of distance in front and behind me so I can react to others actions.

[Jerry]

Excellent post, TC.

A few observations, dealing with my time as an advanced amature photographer. They eye is a mysterious thing. Scientists have learned that various parts of the perform different functions; for example, the rods and cones that interperate color are more packed at the center of the eye and less dense at the peripherals, so although we can "see" at the edges of our peripheral version, motion and color take longer to be recognized than at the center of our vision. There is some evidence that suggests our eyes and brains are programmed to identify horizontal objects more quickly than vertical ones. Bikes are inherently vertical.

Add to this mix the distractions of modern driving and and recognition of bikes is impaired even further. And in my own case, 2 kids, I am constantly surprised how little they "see" when on the road. For example, I can ask them what state the last vehicle they passed was from; not a clue. While anecdotal, this lack of attention to detail seems to be endemic in most drivers.

As a rider of 34 years, I realize that riding has made me a better driver, more acute to situations and surroundings than perhaps a non-rider would be. Still, it seems to me that to many drivers consider their car to be an extension of their living room or office, take much for granted, and don't make the effort to really "see" the road and surroundings.

So, I have four general rules I follow when I ride:

Never assume other drivers see you.
Never take any situation for granted.
Don't assume anything.
Pay special attention at intersections!

The general guidlines have worked pretty well for me so far.

There are physiological and culteral reasons that make riding a motorcycle inherently dangerous. Some background in both arenas should help us survive and get to be better riders.

[xs11jack]

WOW

Your info is excellent. You really can't find the information you presented easily. As Xsilerating said, this information should be available everywhere. You really should copyright it. I am kind of an information junkie on stuff I am interested in, and I learned new things reading your presentation. I can't thank you enough.