speedo accuracy??

[Rocketman]

I suppose looking at this thing from another angle the speed limits are the maximum so in a 30 you should always be driving under 30 not trying to drive exactly at 30 like many of us do.

 

[wookie]

Due to the accuracy of new dash boards which are preprogrammed with the tyre size from factory, breaking the limit by 1mph is now easily punishable but it's always been a punishable offence, reason they didn't was proving the speedo accuracy.

So does that mean that they will continue to be more lenient with drivers of older cars who only have an old mechanical speedometer to rely on ?

 

[rtbcomp]

Hi, Yes, the military stuff would do but I think the 'cooking' version generally available doesn't.

Colin

My tablet does

 

[CompoSimmonite]

Hi, Yes, the military stuff would do but I think the 'cooking' version generally available doesn't.

Colin

I've got an ancient Garmin military spec GPS and it reacts to every step you take ! Just data - no mapping

 

[Justme]

And new implimentation.

How?

 

[Justme]

And new implimentation.

Why do you think that?

 

[Justme]

Just another way to extract more money from legal motorists.

Er how is some one who is speeding legal?

 

[Justme]

Hi, Satnav isn't any more accurate than a speedo because it doesn't take into account going up or down hill for example. It's not accepted as a speedo for the purposes of the MOT for instance (and yes I know it's not tested but has to be present). Digital speedo's will be more accurate because they count the revolutions of the drive shaft, provided it's fitted with the tyres it was calibrated for.

Colin

My digital speedo is no more accurate than my clock. Both read exactly the same & are the same amount out re the sat nav.

PS sat nav does now about hills. It used out on the hills all the time & can tell height as well.

 

[Justme]

You all seem to think that this is a change of implementation / law.

Its not.

Only the fines have changed.

If the allowance would have applied before it will apply still now. Its a discretionary scheme.

It allows prosecution at 1mph over but gives leeway within limits if sensible.

 

[ukracer]

Er how is some one who is speeding legal?

Because over 99% of motorists do so.

Its not speed that causes accidents but dangerous driving.

 

[ukracer]

You all seem to think that this is a change of implementation / law.

Its not.

Only the fines have changed.

If the allowance would have applied before it will apply still now. Its a discretionary scheme.

It allows prosecution at 1mph over but gives leeway within limits if sensible.

And you think they wont rake in as much money as possible.

 

[ukracer]

So does that mean that they will continue to be more lenient with drivers of older cars who only have an old mechanical speedometer to rely on ?

Nope...they wont give two hoots.

 

[hotrodder]

It's not like older mechanical speedos never had to meet any standards and were allowed to under read... the EC Council Directive 75/443* mentioned here https://en.wikipedia.org/wiki/Speedometer#United_Kingdom dates from the 1970s for example

Obviously if it's knackered or someone's messed with tyre sizes or mixed and matched clocks etc under reading is possible but that applies to anything regardless of age. If it's heavily modified or a one off then obviously it would been through an IVA test which unlike an MOT checks speedo accuracy

* http://125.32.98.1/critenon/国外标准/EEC/75443e.pdf is the full directive for anyone that wants to read 23 pages about speedometer approval & testing. Section 4.4 is where the phrase

The speed indicated must never be less than the true speed.

appears

 

[W.olly]

All my speedos have always read slightly under on every vehicle I've owned.
The fines have increased and like the phone thing no doubt the points for speeding will increase one day too.
What ever the money is spent on and whether we like it or not what can we do.
Simple answer really don't exceed the limit.
I'm no goody two shoes mind and I've had a couple of fines/points over the years.

Is that dont break speedo reading or actual speed ?

Old Tachos running the round card could read up to 10% under or over the set check speeds of 40kph and 60kph, that's where the old 10% allowance came from but these old style Tachos are rare and the rules have changed.
New digital Tachos are accurate to with 0.1kph at the given tyre circumference on the calibration day.
Even with a brand new tyre and a fully worn tyre, you are talking less than 0.5kph difference.
Due to the accuracy of new dash boards which are preprogrammed with the tyre size from factory, breaking the limit by 1mph is now easily punishable but it's always been a punishable offence, reason they didn't was proving the speedo accuracy.

I drive a brand new van and i am doing 76 on the speedo but i am actually doing 70, not so accurate here.

 

[Migmac]

After reading this yesterday I checked my speed with my GPS. Upto 10mph there is very little in it, 15 mph and it's nearly 5mph of a difference. It's 5mph out all the way to 50mph. Didn't get above 50mph had my trailer on! The only time the gps and the speedo read the same was when I was stopped

 

[Richard.]

Is that dont break speedo reading or actual speed ?

Try both. See which one works out best for ya.

 

[Justme]

Because over 99% of motorists do so.

Its not speed that causes accidents but dangerous driving.

So that makes it legal?

 

[Justme]

And you think they wont rake in as much money as possible.

Who cares? Dont speed & they cant fine you. Its a simple system.

 

[Rocketman]

Because over 99% of motorists do so.

Its not speed that causes accidents but dangerous driving.

Dangerous driving is speeding. Speeding does cause accidents you are a fool is you believe anything different. The slower you go the more time you have to react.

By the way I'm no nun but at least I have the realisation that every mph you drive faster it reduces the reaction, stopping and avoidance possibilities.

 

[wookie]

Nope...they wont give two hoots.

No surprise there then. I suspected as much.

So that makes it legal?

No, I'll agree with you that speeding is never legal, but if 99% of the population are regularly breaking the speed limit then perhaps the speed limit is wrong and it should be raised. Other countries manage to have higher speed limits on their motorways (for example) without having a higher accident rate.

Personally motorways are one place I would like to see speed limits raised, on the other hand near schools & playing fields etc it should be 20mph or continuous barriers between the pavement and the road, I'd like to see gatso cameras installed next to every school in the uk etc even if this means we have to remove some from dual carriageways and national speed roads.

Dangerous driving is speeding. Speeding does cause accidents

Dangerous driving maybe speeding, but speeding doesn't have to be dangerous driving.

Speeding may cause accidents (apparently it's a contributing factor in 1/4 accidents) but people driving too slow also causes accidents.

There are far more problems that need addressing with people's driving than just speeding, but speeding is an easy one to detect and prosecute.

For example... People not paying attention whilst driving because they are too busy fiddling with their car stereo/using their mobile phone/distracted by children in the car/looking at the passenger when chatting/putting on makeup/having a shave etc etc are all things that should be prosecuted but detecting these actions are a lot harder than just measuring a vehicles speed so the "power that be" have decided to go for the easy target.