Q I never slept with my wife before we were married; did you?

 

A Dunno, what was her maiden name?

did she have a rear wash/wipe?             sorry could resist 

I saw a sign outside a bar in Texas; liquor in front, poker in rear!

Another good reason to keep the rear window clean; the rear-view mirror is flat, the wing mirrors are convex.  Hence only the rearview mirror enables you to correctly judge the distance of following vehicles.

Given an appropriate frame of reference you can use a convex mirror to judge distances.

44 minutes ago, weasley said:

Given an appropriate frame of reference you can use a convex mirror to judge distances.

I disagree; the relationship between apparent size and distance is non linear.   In the US and Canada, flat glass in mandated for the driver's side wing mirror.

 

 

Edited 19 February, 20188 yr by kelper
corrected last sentence

How long have we had convex mirrors? How long does it take to make judgements using them?
It's like arguing with my wife 

18 minutes ago, Urrell said:

How long does it take to make judgements using them?

Judging by the number of drivers who change lanes on the motorway at the last second, forcing me to brake, I'd say many drivers never learn to judge distances.  (and probably don't check their rear view mirror.

 

You may be skilled at this, but most aren't. 

Oh, silly me.  That will explain why I keep reversing into things and pulling out in front of cars on the motorway (NB - I don't do either).

 

A convex mirror gives a wider field of view, but the rate of change of apparent size of an object is still dependent on its distance away and relative speed.  It may not be the same view as seen with the naked eye, or via a flat mirror, but the brain is well able to compensate for such things given an appropriate frame of reference.

 

"…OK, one last time. These are small… but the ones out there are far away. Small… far away…"

4 minutes ago, weasley said:

rate of change of apparent size of an object is still dependent on its distance away and relative speed.

100% correct for a convex mirror.  But for a flat mirror it is ONLY dependant on the relative speed.  When reversing one doesn't need to judge the speed of approach but the distance, and you may have static points of reference.  But on the motorway what points of reference do you have?

On 2/14/2018 at 16:31, kelper said:

I think she meant you!  No one makes you read this thread.

 

Don't you just love a bloke who signed up with the forum just a couple of weeks ago and is already quoting chapter and verse and putting people straight about on just about everything there is to know,  UK Law included, plus sundry other matters that he kindly explains to us numpties.  Not to mention making uncalled for remarks towards a fellow member who has eleven years of valuable and reasoned content behind him on here. I'm just wondering how we all got on before he graced these pages with his knowledge and wit.

 

The most recent lesson being mirrors.  How have I got by these past 50 years using convex mirrors on all the vehicles I drove? ... including, as I recall, twenty eight years of driving fire engines, all equipped with convex mirrors?  That would explain why I had so many darned accidents driving to incidents.   ....   oh, hold on a minute ....

Oh, sorry sir, tipping my hat.  How long do I have to be on the forum before I can express an opinion?  The forum is for debate, after all.

1 hour ago, kelper said:

100% correct for a convex mirror.  But for a flat mirror it is ONLY dependant on the relative speed.  When reversing one doesn't need to judge the speed of approach but the distance, and you may have static points of reference.  But on the motorway what points of reference do you have?

 

Points of reference:

• awareness of how large a car/truck/motorcycle is and a familiarity of how the mirrors distort this
• relative size and location of a vehicle compared to another vehicle in the same field of view
• alignment with other markers in the mirror, such as the side of my car (hence the reason I always adjust the mirrors to include a small portion of my car - I don't agree with this supposedly secret new insiders' way of setting mirrors that do not show your car)
• constant awareness of the rate of change of vehicles and other items in my field of view
• time taken for a vehicle to reach a fixed mark that I just passed (signpost, flyover, road marking etc)
• The amount of the mirror's area occupied by a vehicle
• And so on.

Having driven trucks and towed large trailers you quickly work out how the side mirrors work and how to track vehicles as they move around you.  The USA is one of very few places that demand a planar mirror on the driver's side - the rest of the world copes fine with our hall-of-mirrors setup.

 

Of course, back to the original point, door mirrors AND a rear view mirror are the best set up to have, and a good reason to keep a rear window clean (using the wiper and washer provided rather than any aerodynamic redesign of the car) but in my opinion "only the rearview mirror enables you to correctly judge the distance of following vehicles" is not, in my experience, correct.

Thank you for a well-argued and polite response.  At times I think this forum is a bit brusque! (Brusqoda?)

I do try not to be rude but when some one told me "to get a life" I responded in what I thought was a humorous way.  I don't think my remark was "uncalled for".  But I shall try not to annoy so many people.

Edited 19 February, 20188 yr by kelper

On ‎13‎/‎02‎/‎2018 at 13:13, ben4012 said:

wDon't know of anyone charged with having a dirty rear window. 

 

CUR reg 30 refers to 'view to the front' but does state 'all glass'. Any case law on the matter?

 

 

 

 

Quote

Saw  someone being pulled over by our 'Boys in Blue' in Inverness on Sat (no weapons used) for a dirty rear window, the number plate was too dirty to read as well.

M

Hi KTM690rr, who are you quoting?

 

How do you know why the police stopped them - just curious :-)

 

6 hours ago, kelper said:

100% correct for a convex mirror.  But for a flat mirror it is ONLY dependant on the relative speed.  When reversing one doesn't need to judge the speed of approach but the distance, and you may have static points of reference.  But on the motorway what points of reference do you have?

Every 100m the emergency phone direction post !!

 

M

8 hours ago, kelper said:

I disagree; the relationship between apparent size and distance is non linear.   In the US and Canada, flat glass in mandated for the driver's side wing mirror.

 

 

Look at Trump; there's no accounting for the inability of our cousins to assimilate the simplest of things.

 

M

2 hours ago, kelper said:

avoid Mr Pold.Hi KTM690rr, who are you quoting?

 

How do you know why the police stopped them - just curious :-)

 

I saw them with my own peepers and there were no weapons deployed, so there. I was doing a wheely at the time, so with one wheel to control had plenty of time to observe and avoid.

 

M

Getting back on topic:

As some may know there are quite a few dusty gravel country roads in New Zealand. Despite the Yeti’s acknowledged brick like aerodynamics I’ve found it to be the best vehicle I have owned for not holding dust on the rear window. I suspect this is because the verticality of the rear window allows dust to slough off. If all else fails then fuel stations here have complimentary window squeegees and water readily at hand anyway.

And going back off topic, it doesn’t matter here if the rear view mirrors are flat or curved or if the rear window is dirty because nobody ever looks to see what’s behind them !

10 hours ago, ktm690rr said:

Every 100m the emergency phone direction post !!

You can see those in your offside wing mirror? At 70mph?

53 minutes ago, kelper said:

You can see those in your offside wing mirror? At 70mph?

 

53 minutes ago, kelper said:

You can see those in your offside wing mirror? At 70mph?

No silly, on your nearside.

Any driver with a modicum of driving skill or advanced driving training will tell you that both outside mirrors should be checked as routine, frequently.

 

M

 OK, but I'm not going to be looking at marker posts on the hard shoulder when I'm about to overtake on a motorway.

 

 

@kelper - if you're struggling to judge distance in a convex mirrors and keep the rear screen clear, you should consider if you're safe to be driving.

 

You could try using aftermarket mirrors, at least some on eBay claim to be flat and compatible with a Yeti.

 

As for your rear window:

- ensure you always fill up the washer fluid before every journey

- clean the screen before every journey

- carry extra screen wash and fill up when required

 

If that's not acceptable, sell the Yeti and get a vehicle without a vertical or near vertical rear screen...

 

Not sure if there is anything else you can do given the feedback about mud flaps and spoilers being ineffective.

47 minutes ago, kelper said:

 OK, but I'm not going to be looking at marker posts on the hard shoulder when I'm about to overtake on a motorway.

I could see judging distance a problem with only one eye but not if both eyes are working, as Langers mentioned are you safe to drive given your problem is as acute as that?