Speedo Inaccuracy - Motorway Mileposts

A

Alex

Guest

• Dec 13, 2004

• #1

I've got a speedo/trip both of which I suspect as being wrong, but not
by the same amount. Can anybody tell me exactly how far apart those
little blue/white marker posts are on the Motorway? I know they're
numbered, but I need to know the distance so I can check this.

TIA

Alex

 

S

Si K

Guest

• Dec 13, 2004

• #2

"Alex" <[email protected]> wrote in message
news:[email protected]...
> I've got a speedo/trip both of which I suspect as being wrong, but not
> by the same amount. Can anybody tell me exactly how far apart those
> little blue/white marker posts are on the Motorway? I know they're
> numbered, but I need to know the distance so I can check this.
>
> TIA
>
> Alex

100m IIRC - maybe 100yds - they usually say how far to the next emergency
telephone, and some also have a distance to it too

Si

 

A

Austin Shackles

Guest

• Dec 13, 2004

• #3

On or around Mon, 13 Dec 2004 20:04:47 -0000, "Si K"
<[email protected]> enlightened us thusly:

>
>"Alex" <[email protected]> wrote in message
>news:[email protected]...
>> I've got a speedo/trip both of which I suspect as being wrong, but not
>> by the same amount. Can anybody tell me exactly how far apart those
>> little blue/white marker posts are on the Motorway? I know they're
>> numbered, but I need to know the distance so I can check this.
>>
>> TIA
>>
>> Alex
>
>100m IIRC - maybe 100yds - they usually say how far to the next emergency
>telephone, and some also have a distance to it too

telephones are ISTR a mile apart.

however, the markers have numbers on them in km and tenths, starting from
one end of the m-way. so you can, in the slow lane, say, travel at 60 kph
and have someone time between e.g. 173 and 174 km, and use that to work out
how fast you were really going, if you get an answer significantly different
to 1 minute. Likewise you can use 'em to check yer milometer.

 

S

Stuart Adair

Guest

• Dec 13, 2004

• #4

Its 100yds not 100m.

Stu

"Si K" <[email protected]> wrote in message
news:[email protected]...
>
> "Alex" <[email protected]> wrote in message
> news:[email protected]...
>> I've got a speedo/trip both of which I suspect as being wrong, but not
>> by the same amount. Can anybody tell me exactly how far apart those
>> little blue/white marker posts are on the Motorway? I know they're
>> numbered, but I need to know the distance so I can check this.
>>
>> TIA
>>
>> Alex
>
> 100m IIRC - maybe 100yds - they usually say how far to the next emergency
> telephone, and some also have a distance to it too
>
> Si
>
>

 

S

SteveG

Guest

• Dec 13, 2004

• #5

They are 100m apart, with a positioning tolerance of +/- 1m

The numbers are km (the top row of numbers) & tenths (the second row)
from the start of the motorway.

Regards

Steve G


Alex wrote:
> I've got a speedo/trip both of which I suspect as being wrong, but not
> by the same amount. Can anybody tell me exactly how far apart those
> little blue/white marker posts are on the Motorway? I know they're
> numbered, but I need to know the distance so I can check this.
>
> TIA
>
> Alex

 

D

Dave Liquorice

Guest

• Dec 13, 2004

• #6

On Mon, 13 Dec 2004 20:04:47 -0000, Si K wrote:

> 100m IIRC - maybe 100yds

100m

> - they usually say how far to the next emergency telephone, and some
> also have a distance to it too

I don't think the normal ones have any distance information just the
direction to the nearest phone. Phones are spaced at 1.5km (+/-10%)
on normal motorways but going down to 1km on four lane.

From Google:

http://www.official-documents.co.uk/document/deps/ha/dmrb/vol9/section4/ta7397.pdf

--
Cheers [email protected]
Dave. pam is missing e-mail

 

D

Dave Liquorice

Guest

• Dec 13, 2004

• #7

On Mon, 13 Dec 2004 20:43:48 +0000, Austin Shackles wrote:

> so you can, in the slow lane, say, travel at 60 kph and have someone
> time between e.g. 173 and 174 km, and use that to work out how fast
> you were really going, if you get an answer significantly different
> to 1 minute.

Or find the "measured mile" that is normally near to the local traffic
police HQ. They use it to check their speedos...

--
Cheers [email protected]
Dave. pam is missing e-mail

 

A

apk1

Guest

• Dec 13, 2004

• #8

Better still look out for blue marker posts, normally on dual carriageway
near police garages, these will be set 1 mile apart and used to calibrate
speedo's etc.

Tony

"Stuart Adair" <[email protected]> wrote in message
news:[email protected]...
> Its 100yds not 100m.
>
> Stu
>
> "Si K" <[email protected]> wrote in message
> news:[email protected]...
>>
>> "Alex" <[email protected]> wrote in message
>> news:[email protected]...
>>> I've got a speedo/trip both of which I suspect as being wrong, but not
>>> by the same amount. Can anybody tell me exactly how far apart those
>>> little blue/white marker posts are on the Motorway? I know they're
>>> numbered, but I need to know the distance so I can check this.
>>>
>>> TIA
>>>
>>> Alex
>>
>> 100m IIRC - maybe 100yds - they usually say how far to the next emergency
>> telephone, and some also have a distance to it too
>>
>> Si
>>
>>
>
>

 

D

Dave Liquorice

Guest

• Dec 13, 2004

• #9

On Mon, 13 Dec 2004 22:14:10 GMT, apk1 wrote:

> Better still look out for blue marker posts, normally on dual
> carriageway near police garages, these will be set 1 mile apart and
> used to calibrate speedo's etc.

Didn't I just say that? B-) Though of the 3 or 4 measured miles I
know of the markers have all been different.

The small marker posts on motorways really are 100m apart not 100yds,
the measure the distance of that point from the start of the motorway
in km and 1/10ths of a km. ie 100m.

--
Cheers [email protected]
Dave. pam is missing e-mail

 

D

Disco Duck

Guest

• Dec 15, 2004

• #10

On Mon, 13 Dec 2004 13:36:07 -0600, Alex wrote
(in article <[email protected]>):

> I've got a speedo/trip both of which I suspect as being wrong, but not
> by the same amount. Can anybody tell me exactly how far apart those
> little blue/white marker posts are on the Motorway? I know they're
> numbered, but I need to know the distance so I can check this.
>
> TIA
>
> Alex

I believe because of the way the laws governing speedometers are written it
will be off. Car and Driver Mag had a good article explaining the difference
between American made and European made cars.

The American cars have to be plus or minus two percent. The European cars
have to read high. Everybody I know with a European car will read 75 MPH at a
true 70. That is true of my 96 disco as well. This is checked both with GPS
and Mile markers.

The Odometer should be correct since at least in the U.S. it goes on the
title and must be accurate. Also for the warranty.
Hud