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Auto speed limiter for cars

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Auto speed limiter for cars

Old 12th Oct 2017, 20:26
  #41 (permalink)  
 
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Originally Posted by Carry0nLuggage View Post
Most? Hardly. To account for tolerances the requirement is speedos may under read by up to 10% but not over read (i.e. true speed +10%/-0%).
You've got that the wrong way around.
Speedometers can never under read but can over read.
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Old 12th Oct 2017, 20:47
  #42 (permalink)  
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Aox, and while we are splitting hairs, the Satnav speed can be set to one unit of speed, is that to a plus/minus 0.5 or to exactly one unit?
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Old 12th Oct 2017, 20:55
  #43 (permalink)  
 
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Checkboard

Your post #30 caused me to look at the documentation and it would appear you are correct, kickdown will also disable the mode.

Also, the 'Intelligent Speed Limit Mode' in addition to that allows it to be varied by up to +6mph.

I look forward to experimenting, and thank you for prompting me to further increase my understanding of the system, which is looking better as a result.

Notwithstanding all of the above, obviously the driver retains ultimate responsibility for his/her vehicle!
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Old 13th Oct 2017, 08:45
  #44 (permalink)  
 
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Linking this thread the driving in the South East* one, you can keep your cruise control. Give me a crawl function with improved gearing and engine management at low speeds anyday!

*Other congested conurbations are available in the North
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Old 13th Oct 2017, 09:20
  #45 (permalink)  
 
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I followed a Police car doing 65 in 60 limit. Not just one, but I hardly ever see these cars sticking to the published limit. Why should I?
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Old 13th Oct 2017, 09:29
  #46 (permalink)  
 
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One reason for some speeding may be that it seems to be common knowledge that car speedometers over-read. This used to be to allow for the inevitable innaccuracies in an analogue instrument driven by magnetically induced eddy currents in the disc/drum that was connected to the needle, but nowadays most cars seem to have extremely accurate speedometers.

For example, my last two cars have what looks to be a constant 10% over-reading up until 50 mph, then a constant 5 mph over-read above that speed. Other owners have reported the same finding, from comparing GPS speed to the speedometer speed.

Originally Posted by Sciolistes View Post
I followed a Police car doing 65 in 60 limit. Not just one, but I hardly ever see these cars sticking to the published limit. Why should I?
If those police cars are the same as mine, in terms of indicated error, then they may well have been driving at 60 mph on their calibrated instrument, but your car could well, like mine, be indicating 5 mph over at a true 60 mph, so showing 65 mph.


The speed warnings that come up when using the GPS nav system are always based on GPS speed, rather than indicated speed, so you can drive at an indicated 33 mph and still just be OK in a 30 mph limit, for example.

I've found that I tend to automatically compensate for the indicated speed error, mainly because I end up getting tail gated if I don't, and this suggests that others do exactly the same thing, or that they just aren't aware of their speed at all............
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Old 13th Oct 2017, 09:59
  #47 (permalink)  
 
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My car has a consistent over-read of just under 10%. 32 = 30, 54 = 50 and 76 =70. The cruise control can be used in 4th, 5th & 6th gear and is speed and not fuel flow dependent. Given an empty road I cruise at (ahem!) a shade over the limit. So I overtake most lorries but obviously not white Mercedes panel vans, stupid little tarts doing their lipstick and Facebook updates in little French cars and never an Audi, the current replacement for BMWs, whose drivers appear to have all the charm, consideration and generousity of Mugabe.

PM
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Old 13th Oct 2017, 10:30
  #48 (permalink)  
 
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Originally Posted by Romeo Charlie View Post
That certainly wasn't the case when I did my Speed Awareness Course. ......
Interesting. The difference may lie in jurisdictions.

Unofficially and soon to be reviewed so I'm told, in my local jurisdiction in Oz, police have historically allowed a 9-10 km/h window of grace above the posted speed limit.
Combine that with the built-in inaccuracy in the speedos and it becomes clear that with only a few exceptions, those actually booked for speeding had to be aware that they were exceeding the limit and chose to ignore it.

Especially true in freeway traffic where most of the vehicles may be cribbing a bit but at least maintaining position in the traffic stream.

I understand that the comments from your group were probably quite genuine, but the oik weaving his way from lane to lane in the above scenario will always say that he didn't know that he was speeding when pulled over.
And anyone consistently driving 10-15+ km/h over the limit without realising that they're doing it needs more than a buzzer, unless it's the cattle-prod type.
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Old 13th Oct 2017, 10:35
  #49 (permalink)  
 
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I can't be sure, but I seem to remember that when our village was trying to get a 20 mph zone down the very narrow "high street" (which it now has) we were told that there was a "zero tolerance" policy for all those exceeding the 30 mph limit here.

I only remember it because I'd always though you were allowed a few mph over the limit before getting a ticket, and I'm pretty sure that's still the case on motorways, as an awful lot of cars seem to get away with driving at around 80 mph pretty much all the time.
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Old 13th Oct 2017, 10:49
  #50 (permalink)  
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14 people [out of 19] caught in a 30, most had either no idea they were speeding or no idea of the limit at that time.
The auto speed limiter system selected ON would have kept them out of trouble.
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Old 13th Oct 2017, 10:58
  #51 (permalink)  
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Originally Posted by Discorde View Post
The auto speed limiter system selected ON would have kept them out of trouble.
Better still, how about actually having the ability to drive without disguising this inability by becoming reliant on technology.

Speed limits.....usually displayed on large signs at the side of the road.

Mk1 eyeball. View these limits. Mk 1 eyeball. Check speedometer to comply.

Brain ( this is where it can get problematic it seems ) engage and then control speed through application of right foot to throttle.

Result....no speeding above prescribed limit.

Difficult for so many it seems.
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Old 13th Oct 2017, 11:01
  #52 (permalink)  
 
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Overtaking:-
It makes my blood run cold when I see a speed limit obsessed overtaker inching past a slightly below limit car (even one which does NOT accelerate whilst being overtaken), as oncoming traffic materialises on the horizon.

PS A clown tried to outdrag the TVR recently - waste of time - but he severely embarrassed the next car which tried and (prudently) failed to pass him. Not sure how such drivers' "brains" are wired.
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Old 13th Oct 2017, 11:04
  #53 (permalink)  
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KnC: to retain the skills you mention, practise occasionally with the system OFF.
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Old 13th Oct 2017, 11:16
  #54 (permalink)  
 
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Originally Posted by VP959 View Post
I can't be sure, but I seem to remember that when our village was trying to get a 20 mph zone down the very narrow "high street" (which it now has) we were told that there was a "zero tolerance" policy for all those exceeding the 30 mph limit here....
There has been recent discussion in West Oz about instituting a zero grace policy.
I am sure that such already exists in certain circumstances (eg road repairs) and police would probably deny that it exists at all.
But, on good advice, it has existed informally for a long, long time.

In the remote north-west you could generally get away with +19 km/h on the open road provided your car was wearing local district plates.

How anyone runs off a 30 km dead-straight, flat road section and into the only tree within 100 km defies imagination. But inevitably, speed is quoted as a factor.
Or should those incidents not go straight into the Darwin Awards.
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Old 13th Oct 2017, 11:20
  #55 (permalink)  
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Originally Posted by Discorde View Post
KnC: to retain the skills you mention, practise occasionally with the system OFF.
In theory, a good idea. In practice, once automation is being used as a matter of course, how many drivers would be inclined to revert to manual.

Not many, if any as they have no inclination to do so, technology now taking precedence over, and thus disguising, their inabilities.

Better still, don't use the system in the first place.
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Old 13th Oct 2017, 11:24
  #56 (permalink)  
 
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Originally Posted by Krystal n chips View Post
Speed limits.....usually displayed on large signs at the side of the road.
The last time I got a ticket I assume the signs were actually there, but I failed to see one of them through a couple of lanes of non-transparent juggernauts. The limit on this road had changed multiple times between 30 - 40 - 50 - 60 over the preceding couple of miles, and to me there was no obvious natural limit for each of these few-hundred-yard sections.
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Old 13th Oct 2017, 11:29
  #57 (permalink)  
 
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Originally Posted by WingNut60 View Post
How anyone runs off a 30 km dead-straight, flat road section and into the only tree within 100 km defies imagination.
Driver fell asleep.

I fell asleep once, driving a motorbike. From the top of the hill I could see the red traffic lights at the bottom, half a mile or so ahead, with a queue of cars. Next thing I knew I was approaching the back of the queue from a few yards away still at full speed (this was a Honda C90 so around 55mph seeing as it was downhill). Pull to the right round the queue just missing the rear car, braking but going too fast to stop before getting to the lights, and just as I passed through the traffic lights they started changing.
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Old 13th Oct 2017, 11:32
  #58 (permalink)  
 
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Overtaking:-
It makes my blood run cold when I see a speed limit obsessed overtaker inching past a slightly below limit car (even one which does NOT accelerate whilst being overtaken), as oncoming traffic materialises on the horizon.

PS A clown tried to outdrag the TVR recently - waste of time - but he severely embarrassed the next car which tried and (prudently) failed to pass him. Not sure how such drivers' "brains" are wired.
Yes the safest way to pass is as fast as possible to eliminate that danger zone
It is very dangerous seeing cars accelerate to the speed limit and then crawl past

Another thing motorists forget is to also Brake out of an overtaking manoeuvre which is going wrong

As with aeroplanes in this modern high technology world how many are taught to control a car rather than just driving it ?
Power (and brakes) are your friend
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Old 13th Oct 2017, 11:33
  #59 (permalink)  
 
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Originally Posted by Gertrude the Wombat View Post
The last time I got a ticket I assume the signs were actually there, but I failed to see one of them through a couple of lanes of non-transparent juggernauts. The limit on this road had changed multiple times between 30 - 40 - 50 - 60 over the preceding couple of miles, and to me there was no obvious natural limit for each of these few-hundred-yard sections.
Yes, that certainly happens.
Sometimes you know that you have probably missed a limit sign and that can be unnerving.

I am in favour of any technology that makes the task easier and safer.
But like the magenta line, if you should ever become subservient to it then you do so at your own peril.
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Old 13th Oct 2017, 11:37
  #60 (permalink)  
 
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Originally Posted by Gertrude the Wombat View Post
Driver fell asleep.....
Yes, that's about the only explanation; that and suicide.
But when you see the forlorn little cross(es) at the base of that lonely tree you can only shake your head.
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