Hi I know that U K roads are designed in metric. Does anybody know when they stopped using imperial for road design?

Don't know about the design, but:

*Roads are marked in yards and miles
*Bridge heights are marked in feet and inches
*Weight for bridges seems to be measures in both Imperial tons and Metric tonnes

Metric units have been used for the design of British roads since the 1970's, but road signs that are in place for the benefit of motorists are still in Imperial units except for weight limits which are given in tonnes (prior to about 1980 they were either in cwt or tons and cwt) and bridge heights, some of which are in dual units.

Road markers on the sides of the road (which are impossible to read unless you are a passenger and the driver is in the "slow" lane) are in kilometres and tenths of a kkilometre. I recall seeing some in miles and furlongs in about 1980, but they have disappeared.

The present situation then is that as far as road engineers are concerned everything is in metric, but as far as the ordinary driver is concerned, everything is in Imperial apart from weights (in tonnes) and bridge heights (dual units).

What I mean is that some signs are evidently marked in Imperial tons (marked before we changed) and other signs are marked in metric tons. No one knows which is which. No one cares (because they are so close in size)

John M wrote

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So, if a sign just said 5 t (meaning 5000 kg)
>>

In practice all the weight limit signs have an upper case thus "T" (though the road sign regulations do permit the use of a "t"). The use of an upper cae "T" is technically in breach of the Weights and Measures Regulations 1986 (which make the EU directive 80/181/EEC part of UK law). The W&M Regs state that the symbol for "tonnes" is "t" while the symbol for "teslas" (a measure of magnetic field strength) is "T". The W&M Regs also prohibit the use of Imperial tons for any "legal, commercial, administrative or public health" use.

To date, I have not heard of anybody using this as a defense for ignoring a weight restriction limit, but no doubt one day a lorry driver, who stands to lose his licence if found guilty of ignoring such a sign will find a smart lawyer who will use this to get him off the hook.

Weight signs in the UK show tonnes, tons, "t" and "T".

Also CWT can be seen - their is one approaching the warehouse "shoppery" near where I live.

Heights and widths are either dual marked or imperial only. Imperial outweigh metric here.

Those markers by the motorway are not designed to be used by the public - but are meant for road recovery. Ask anyone how far apart they are and no-one will know.

Indeed I've seen some that are just a few feet away from each other (I'm thinking M25 here).

I suspect it's a bit like the "3 - 2 - 1" marker boards which are "meant" to be 100yds apart.

Finally "people who still use imperial on the road" counts for the vast majority - esp on the issue of miles versus km where it's in the high 90's %.

P.S. Martin - somethin to think of regarding your hatred of the use of ' and " for height and width instead of "ft" and "in".

In wales all signs are dual language. In welsh "ft" and "in" don't mean anything. " and ' mean the same to a welsh speaker as to an English one. PErhaps that's why they use ' and " (apart from total familiarity)

>>Those markers by the motorway are not designed to be used by the public - but are meant for road recovery. Ask anyone how far apart they are and no-one will know.

Indeed I've seen some that are just a few feet away from each other (I'm thinking M25 here).

I suspect it's a bit like the "3 - 2 - 1" marker boards which are "meant" to be 100yds apart.>>

First of all, the guy was asking about the design of roads, not what type of signs one sees. I'm sure if he came to England he can see for himself what the signs are like. But road construction is not visable to the naked eye.

Second, since the roads are indeed designed and constructed using metric, then the survey posts along the side of the roads would be meant to be 100 m apart and not 100 yards. Before you go spewing lies, why not check the regualtions first and see what the true distance is?

SteveH wrote

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P.S. Martin - somethin to think of regarding your hatred of the use of ' and " for height and width instead of "ft" and "in".

In wales all signs are dual language. In welsh "ft" and "in" don't mean anything. " and ' mean the same to a welsh speaker as to an English one. PErhaps that's why they use ' and " (apart from total familiarity)
>>

I am stating the law as I understand it - the concessions that were negotiated by Mrs Tatcher with our EU partners. (The letters "ft" and "in" appears in all 12 versions of the 181/80/EEC directive) If the signs with single and double apostrophes are ever challenged, they will be challenged on the basis of the law.

Martin - but do you see my point about ft/in being an issue in dual language areas whereas ' and " won't get that issue?

"Euric"

"First of all, the guy was asking about the design of roads"

Correct - and to this degree the discussion has drifted away from the original intent of the question - a bit like suddenly harping on about "dollar hegemony" for example.

"the survey posts along the side of the roads would be meant to be 100 m apart and not 100 yards"

Not once did I say that the posts at the side of the road were yards apart - I was referring to the 3-2-1 marker boards at exits. Of course you won't know what 3-2-1 marker boards are because you've never been here.
I also noted that some of those posts martin was refering to are certainly not 100metres apart - I've seen some that are just a few feet apart.

"Before you go spewing lies"

I leave that job entirely with you - and you can be certain that your lies are entertaining rather than bothersome!

Response to SteveH

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Martin - but do you see my point about ft/in being an issue in dual language areas whereas ' and " won't get that issue?
>>

I understand fully what you mean - I was brought up in a bilingual country (South Africa) and I spoke both languages with a reasonable degree of fluency. However, the EU directive, as I understand it, only makes provision for the use of "ft" and "in". If you visit
http://europa.eu.int/eur-lex/en/consleg/pdf/1980/en_1980L0181_do_001.pdf

you can see the directive in full. BY changing the two occurences of "en" in the URL to "de", "es", "fr" etc you can get the directive in any of the other languages of the EU. All of them show the symbol for feet and inches as being "ft" and "in". I am not trying to justify the use of these symbols, what I am saying is that Mrs Thatcher sold the Welsh short when her ministers negotiated the British opt-outs regarding feet and inches.



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Not once did I say that the posts at the side of the road were yards apart - I was referring to the 3-2-1 marker boards at exits. Of course you won't know what 3-2-1 marker boards are because you've never been here.
>>

If you visit
http://www.highwaycode.gov.uk/signs07.shtml
you can see a picture of the 3-2-1 countdown marker boards. At soem motorway junctionsthey are 100yds apart, at others they are 100m apart.


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I also noted that some of those posts martin was refering to are certainly not 100metres apart - I've seen some that are just a few feet apart.
>>

I find that hard to believe - the posts that I am talking about have a blue band and a number on the blue band. They are actually illustrated on the BWMA section on roads.

"you can see a picture of the 3-2-1 countdown marker boards. At soem motorway junctionsthey are 100yds apart, at others they are 100m apart."

It does not say metres - it says that its not necessarily 100yards apart. It could be 120 metres, 80 yards anything - but they will be equidistant.




<<
I also noted that some of those posts martin was refering to are certainly not 100metres apart - I've seen some that are just a few feet apart.
>>

<<I find that hard to believe - the posts that I am talking about have a blue band and a number on the blue band. They are actually illustrated on the BWMA section on roads. >>


On the M25 is a good example of these - the are near jnc 8 in this particular example .

They also have "telephone 25 yards" at each phone

I won't be stopping to take photos though!