Blind sport warning is too subtle

I'm certainly a fan of driving safety and accident avoidance technology.  The best accident is assuredly the one you never have.

Our new Tesla has far more sensors and assistive technologies than any car we've ever owned.  While I love the minimalistic design of the interior and interface, unfortunately, when it comes to the blind spot warnings, the interface is just far too subtle.

Both friends and family have stated that they would really like the blind spot warning to be embedded in the mirror like many other makes, which is a suggestion with which I completely agree, although retrofitting existing vehicles, as Mr. Musk has previous commented on, is often impossible.  I do believe, however, that it is possible to communicate this alert very well using the dash, but it has to be very noticeable.

I would really like to see the blind spot warning / side collision warning rendered as a color / pattern in the neighboring lane, as illustrated below.  When if may be dangerous to enter a lane, that lane should be colored and patterned accordingly.  Now, I’m not an expert on what would make a good design, but I would start with a fading yellow with a blind spot warning symbol for the condition where entering a lane may be possible yet more caution is advised.  For the case where a collision is near eminent, the lane should be marked as a bright flashing red and white combination (although the video only has red because I wanted to get it done in a hurry). Flashing the alert is important in order to call attention to the severity of the issue since motion is easily detected even in the peripheral vision of the driver and does not rely on color vision.  Any alert that you are going to crash the car needs too be unmistakable and extremely visible to all.

I'll try to develop better renderings in the future.  This was about as good as I could do in 5 min without using PS.

My rather crudely drawn warning indicating that it may be unsafe to enter the right lane.  For the safety conscience, the car was in park and I was not driving when the base photo was taken.

Updated quick, crude sketch demonstrating a flashing warning to the driver that it is unsafe to enter the left lane and that corrective action should be taken.

Now, let's look at how it is actually implemented in the car to see how much suggestion compares with the existing designs.  I'll start with the older system since I'm a bit more familiar with it and have actually seen it in action (I was not driving).

Version 6.2

In this version of the software, if the car detects another car or object in your blind spot, the system shows you a single white line under the main speedometer / energy meter widget (as seen in the lower right in the image I yanked from the manual).  If you happen to get too close to that object, or another car, then the double red lines (lower right) appear, an audible cue is sounded, and the steering wheel vibrates.

Blind spot warning in v6.2 from the Tesla Model S Release Notes (© 2015 Tesla Motors)

This sounds like it has all bases covered -- visual, audial, and tactile -- so what's wrong?  First, it's quite a mental step to go from abstract line to "blind spot".  Second, and most importantly, you have to notice that the lines are even present.  This involves both looking at the dash instead of the road and noticing that this little line has appeared.  While aesthetic it's quite demanding of the driver for something so important.

Let's focus a bit more on those double red lines.  Surely that dire warning is noticeable right?  Well... not really.  It's not as noticeable as you might expect when you're changing lanes, which of course is when you're likely to get this warning.  First, the tactile sensation can easily be confused or ignored. I don't have first hand knowledge of the tactile feel, but I assume that the driver mistook it for the lane departure vibration.  This is easy to do because (1) the vibrations can be triggered by things other than lane departures, such as seams in the concrete and (2) if you don't follow best practice and use your turn signals, then every lane changes causes a drift warning.  Second, the audible cue requires the driver to notice and mentally connect that to the warning (and not something else), and that's only if you even have the ability to hear it.  And finally, those two little red lines require the same mental cognition as the single white line above.

By the time one parses through all of that visual information, assuming one even notices the dash given that they are supposed to be checking the emanating, maybe the rear view camera, listening to the audible alarm, feeling the vibrating steering wheel, etc. it feels like the most relevant information -- that your rear passenger side is about to collide with another vehicle -- is completely lost.  This is a real shame.

In short, while the basic concept is very good: combine audio, visual, and tactile sensations, I'm not sure that the details are quite right.  Each of the cues is just too subtle, especially the visual indicators, and fusing them during a "rare" event might lead to confusion or other driver error.

Version 7.0

While I definitely like the more minimalistic and modern approach of v7.0, as far as the blind spot warning is concerned, the visual indication may even be worse than v6.2!  This is precisely because v7.0 tries to give you more information in the form of flowing lines emanating from the ultrasonic sensors.  Visually it's a very aesthetic representation, but it feels as if aesthetics and subtle elegance have trumped the real goal: safety.

Blind spot warning in v7.0 from the Tesla Model S Release Notes Notes (© 2015 Tesla Motors)

In the visual for v7.0 notice how much visual clutter you have to parse to understand the warning.  Is it referring to the yellow front left sensor?  Maybe I'm too close to the black car in front of me?  No?  Is it the other white lines?  Oh, dang, I know it's that tiny red sliver in the back right!

But wait!  The story of how v7.0 is worse than v6.2 is not over yet.  Oh, no.  Sadly it gets much worse.  For you see, that tiny red sliver in the rear right of the car warning you of danger only does you any good if you can actually see red. What if you are among the ~8.5% of people who don't have normal trichromatic color vision?  (See color blindness on Wikipedia for details)

I am just going to give some quick examples of what the warning looks like for people with the two most common forms of red-green color blindness as well as for people without color vision entirely.  See if you can spot the important alert, which should be just behind the left bumper.

This is approximately what the blind spot warning would look like to someone with Deuteranopia.

This is approximately what the blind spot warning would look like to someone with Protanopia. 

This is approximately what the blind spot warning would look like to someone without color vision entirely.

With all three of these images, notice that not only has the red hot spot disappeared, but that in many cases if could be difficult, if not impossible, for a driver to quickly discern whether or not the warning was due to the lines emanating from the front right or rear left.

I can already hear the critics commenting that you can tell where the warning is by context and that if you are driving defensively, then it really doesn't matter because the driver would stay put until all of the warning lines have disappeared.

All of that may well be true, but this isn't a win-lose proposition.  Designing for wide range of people, who all have different abilities or needs, generally makes the final result more understandable and useable for all, not less.  There is a fine line between being too distracting and being visible enough, but I suspect that a good compromise can be reached; sadly it just isn't the design present in v7.0.

I still love my Tesla though.