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Driver's seat height safety problem

Discussion in 'Gen 3 Prius Accessories and Modifications' started by Bruce vanNorman, Jun 2, 2013.

  1. Bruce vanNorman

    Bruce vanNorman Junior Member

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    --- yes, eyes checked last month. I think not being able to use the break would be even more inconvenient :)

    UPS says that the medium firm booster cushion will arrive sometime this Wednesday. These driver's seat boosters are wedges ~1" in front, ~3" in back and 14" deep (seat is ~17" deep). I also want to make sure that her head is at least 10" from the airbags.
     
  2. Bruce vanNorman

    Bruce vanNorman Junior Member

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    --- what a great idea, thanks. I am a conservative old fusspot. One experiment at a time. There is no expectation that the current experiment will "solve" my wife's visibility issues; but, rather just optimize the "as is" factory configuration.

    I have another experiment in the pipeline - with no parts purchased or ordered.
    - a second driver's booster seat - extra firm (> 200 lbs) possibly sown to the one on order for stability.
    - a lumbar (firm) cushion because she would be above the built in one.
    Objective: reduce the amount of driver's seat cranking up & down - currently 2 to 3 times per day.

    She is already using one of our kitchen cushions and it does improve her visibility. Lift is just a bit over 1" and it is not wedge shaped. You are right, stability is very important. I call these things experiments because they are allowed to fail.

    One failed experiment was a stick on 2" convex mirror. That's where I learned that she was aware of the existence of cars in the "blind spot" but uncomfortable with their actual displacement, velocity, and acceleration. Yes, I am an engineer.

    I need to figure out how to temporarily mount the suggested mirror without installing holes. Double sided mounting tape should hold for an hour or two.

    Thanks again - great idea.
     
  3. ataylor2

    ataylor2 Member

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    Might be off base, but this seems like a big safety concern for you and your wife, why not get a car that fits you two better? Overall you might be opening yourself to more liability with all this. I know if I was hit and injured by someone with all these types of mods in a car, a lawyer would have a field day.
     
  4. 32kcolors

    32kcolors Senior Member

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    Maybe if the OP tinted his windshield 5% limo dark, but this is nonsense.
     
  5. Bruce vanNorman

    Bruce vanNorman Junior Member

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    --- an automotive "convex aspherical lens" is usually in the form of a Fresnel lens made of flexible optical grade plastic. Sold in RV shops in the $10 to $20 range for use in the rear window of an RV. They typically provide 27 degrees down beam, 17 degrees to the side, and can be cut to shape with good pair of scissors. Usual size is ~10" x ~7". Just spray water on the window and the lens sticks. It is also easy to remove and leaves no damage. I had one in my VW combi bus for 20 years. After the driver's seat issues have stabilized. I intend to install one in the passenger side triangular "port hole" as the pillar blocks the visibility of bicycles coming from that particular direction.

    Given a 10 degree down angle from the driver's position, the cumulative lens down beam is ~37 degrees. Trigonometry tells me that road level objects (curbs etc) can be clearly seen as close as 2' from the car.

    - Neither of us can see the rear "port holes" much less what is on the other side (I am 6'2"). Our heads don't swivel that far any more.
    - We've had the Prius for 3 months and are still getting used to it. We had our previous car for 22 years and had gotten very used to it :)
     
  6. Bruce vanNorman

    Bruce vanNorman Junior Member

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    --- Good points!

    The reason for all these types of mods is that they are experiments - which can fail. Most will. Which explains why I am looking primary at removable mods. I appreciate the liability issues (I write "Letters of Engagement" and "Letters of Acceptance" for professional gigs - I specialize in termination liability issues) and intend to do my due diligence.

    In retrospect, a Hybrid Camry may have been a better choice (wrap around rear window), and we probably should have rented a Prius for a few weeks prior to purchase. It took over a month for these issues to surface. Cars have changed over the last 25 years (Duh!). I had a 1990 Honda CRX and my wife had a 1992 Honda Accord. Since these were personal cars, we had the seat tracks modified. Now, in retirement, we are down to a single car. The Prius is optimized for our kinds of use - unfortunately, not for our kinds of body :)
     
  7. JoeS

    JoeS Member

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    You could try changing how your position the side view mirrors. Google(won't let me post a link) car and driver blind spot

    This can be disorienting but helps eliminate blind spots once you are use to it.
     
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  8. jhinsc

    jhinsc Senior Member

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    I think this is likely the best solution. I don't understand the lack of visability issue. With all the glass around, I think it's one of the best cars for visability. Also, I know we'll all get there someday, but I see more and more seniors relying totally on mirrors and shall I say "guess work" when backing up, changing lanes, etc. Even with electronic aids, nothing replaces turning your head to see where you're going.
     
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  9. 32kcolors

    32kcolors Senior Member

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    Just because it has lots of glass doesn't mean it has better visibility. If anything, the blind spots created by the A-pillars are worse than other cars and you can't really see the nose of the car.
     
  10. jhinsc

    jhinsc Senior Member

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    It doesn't have better visibility if you don't look. Blind spots don't just pop up. When you're driving a vehicle, and it has "blind spot", as the driver you compensate and make sure you can see what is being "blinded" from your field of vision. Too many people drive as if they're on auto pilot, assuming as they make lane changes, back up, or make turns, they don't need to look to see if there is anything that might be in their path. Mirrors are very useful, but they can't make up for people's deficient driving skills.
     
  11. 32kcolors

    32kcolors Senior Member

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    That's why I indicated in post #10 that we compensate by becoming more aware of our surrounding in those areas, but that doesn't change the fact that it's a bigger problem in the Prius relative to other cars.
     
  12. jhinsc

    jhinsc Senior Member

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    I disagree - I don't think it's any bigger of a problem than any other car. 2 cars ago, I had a 2008 Honda Accord. Not only could I not see the end of the front , but I couldn't see where my trunk/rear bumper ended either. I love that the Pri's have glass that go all the way to the back end. I think that's why some people think they're being tail gated because the back end of the vehicle ends where the glass ends. Visibility out back is so much better than many vehicles on the road today.
     
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  13. ockevin

    ockevin Active Member

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    My wife is 5'2" tall and no problems what so ever driving
    the car
     
  14. 32kcolors

    32kcolors Senior Member

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    While all these may be true, it still doesn't change the bigger blind spot problem created specifically by the A pillars and many members agree it's a problem, not just me.
     
  15. jhinsc

    jhinsc Senior Member

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    I agree that A pillars are becoming more of a problem as they are increasingly beefed up. But they are becoming more prevalent as vehicles are designed to meet ever stringent crash standards so I don't see this problem going away any time soon. Maybe we'll get technological breakthroughs that will allow thinner pillars cost effectively, but until then it's something we'll have to live with and adapt to.
     
  16. Bruce vanNorman

    Bruce vanNorman Junior Member

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    experiment interim status report:
    Fresnel lenses:
    I bought a 11" x 14" one ($24 incl tax) yesterday. I cut out pieces for two of my experiments. Unfortunately, I blundered, and both pieces were mirror image of what was required thus cannot be used as final solutions. However, I can and did install them on the outside of the car for testing purposes.

    Observation: the 11" x 14" form factor provides too much light bend near the edges (especially the corners) and internal reflection exceeds refraction.

    The piece affixed to the rear (vertical) window (a'la the use closest to the manufacturers intended) works brilliantly. It is mounted on the inboard edge of Toyota's etched tag which is on the passenger side of the glass - where driver's visibility is not blocked by the rear passenger side headrest. My test deployment shows that if "blind spot" objects can be seen in the side mirror, but not in the lens, then object is too close to pull in front of (< 6'). Conclusion: this configuration has some possibilities.

    The piece affixed to the passenger side front port hole nominally works as I hoped, but suppresses too much of the potential image to be considered safe (reflection exceeds refraction).

    Def: "blind spot". The area to the passengers side and behind the driver's seat that could contain a passing vehicle. I consider the area to be blind, even if the car can be seen, when the ability to judge relative displacement, velocity, and acceleration is compromised. Eliminating the "blind spot" usually requires that the area can be scanned via two or more windows / mirrors simultaneously.

    I will get two of the 8" x 10" lenses for further testing.
     
  17. Bruce vanNorman

    Bruce vanNorman Junior Member

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    - visibility experiment report:
    - booster seat:
    The Large Medium-FIRM Wellness Seat Cushion. Sold by TravelMate from Amazon.com ($26.50). Size: 18" x 14" x 1-3/4" to 3-1/2". Color: black.
    has worked out perfectly. My wife's eye level is at the optimal (and target) height. She reports that her ability to judge the position of cars in the passenger side lane "blind spot" is much improved. These cushions and the factory seat do compress a bit, so weight is an important consideration.
    The only negative is that the cushion does not self-center in the Prius's bucket seat. A rather trivial detail to my wife.
    The 18" width is appropriate and the wedge shape (along with the 14" depth) does not seem to affect pedal reach.
    - Fresnel aspheric lenses:
    I will install the final (a cut down 8"x10") rear window lens later this week.
    - Then we will let things stabilize for at least a month before reevaluating the situation.

    Thank you all for your contributions and ideas. Meanwhile, I'll continue monitoring this forum.
     
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  18. ChaiLove

    ChaiLove Junior Member

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    I am 5'3" and do not have issues regarding judging other vehicles or forward visibility in the Prius. I wonder if part of the issue for her is that with the curve of the hood you cannot actually "see" the front end of the Prius when seated in it (or at least not at my height). This is a common issue now with newer cars that are more aerodynamic. She might benefit from practicing using what is referred to as visual reference points when driving. In addition, I do agree with her about the posts on the side obstructing that small area of view. I just accommodate for that by driving slowly in areas where a pedestrian might jump out and by often moving my head position to the side for a quick check that there is nothing there and then returning to my usual head position. I guess that I should mention also that I am a driving instructor.

    Reference points: To know exactly where the vehicle is located, at speeds under 25 mph the young driver
    can align some part of the vehicle with the roadway. Practice establishing left, right, and front reference points 10 or 12 times during each session. Exchange places with your child to demonstrate using left, right and front reference points.

    Left-side reference point: To align the vehicle 3-6 inches from a pavement line or curb on the driver’s side
    of the vehicle, the driver should stop when the line or curb appears to intersect a point located about one foot from the left edge of the hood of the car. After stopping the vehicle, the student should place it in park, set the parking brake, and get out of the vehicle to check whether the vehicle is in the desired position. If it is not, the student should try again.

    Right-side reference point: To align the vehicle 3-6 inches from a pavement line or curb on the passenger’s
    side of the vehicle, the driver should stop when the pavement line appears to intersect the center of hood. The student should get out of the vehicle to check whether the tires are 3-6 inches from the line, and make adjustments as needed.

    Front reference point: To align the front bumper 3-6 inches from a pavement line or curb, the driver should
    stop when the line appears under the passenger side mirrors. Ask your child to get out of the vehicle to check to see whether the front bumper is 3-6 inches from the pavement line or curb. Adjust as needed and re-establish the window sill reference point.

    Hope this helps!
     
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  19. Bruce vanNorman

    Bruce vanNorman Junior Member

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    We both have been doing a bit of your suggestion, here and there, for some time. I'll keep your points in mind. We both have handicap placards and find that bounding in and out of the car somewhat challenging - not to mention downright painful :)

    Since you are a driver instructor: According to some of our friends, insurance rates will escalate when we are over 75 (not that far away) unless we take senior driver's refresher courses. Is this true?

    Ref. Right side reference: Just for yucks, I measured just how close to the passenger side of car I could see a curb from the driver's seat. Laterally, no closer than 16' 8" and I am 6' 2". I haven't done the trigonometry yet. And, this being a Prius - what hood?

    The "visibility problem" is not in detecting objects in "the blind spot" but in judging their relative displacement, velocity, and acceleration - in short, is it safe to change lanes? Obviously, we are concerned about 4 lane highways, which around here, are 45 MPH. Then there are the freeways ... The rear mounted wide angle Fresnel (RV) lens is proving to be quite a help.

    A pleasant side effect of the booster cushion is that my wife (and consequently, myself) do not have to maintain the driver's seat in the full upright position (trays folded :). The Prius headrest pushes forward quite a bit. We now have the seat reclined to the third detent position and it is a lot more comfortable.
     
  20. ChaiLove

    ChaiLove Junior Member

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    Your rates will increase no matter what because at a certain age older drivers are essentially put back in the same category as teen drivers as far as risk with driving. Contact your insurance company because discounts vary by state and company. You would think I could get a discount for what I do but Virginia does not allow it. Also, be sure to not drive with the handicapped placard hanging from the mirror. Most people don't realize that if you actually read the placard it says on there that you should not be driving with it hanging on the mirror (it is a driving pet peeve of mine).