Possible hybrid 'Imperial & Metric' distance signage on some selected roads

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the cheesecake man
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by the cheesecake man »

M4 Cardiff wrote: Sun Apr 11, 2021 23:05 The one area where the process has been started and really needs to be completed as soon as practicable is dual-signing vehicle dimension restrictions as it may reduce some instances of vehicles getting stuck, if the driver only knows their size in metric. How is a German trucker supposed to know whether or not his 4.75 m truck will fit under a 13'6'' bridge?
They could find out before visiting a country they know has imperial signs, just like they'd make sure they know which side of the road we drive on etc. Or they could stop and phone their depot if they're not sure?
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Jim606
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by Jim606 »

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Dual Mile/Km road sign USA
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KeithW
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by KeithW »

There are a number of places in California and Arizona with metric signage, all to do with the proximity of the Mexican Border I suspect.

Here is an example on I-19
https://www.google.co.uk/maps/@31.53660 ... 6656?hl=en
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Vierwielen
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by Vierwielen »

M4 Cardiff wrote: Sun Apr 11, 2021 23:05 The one area where the process has been started and really needs to be completed as soon as practicable is dual-signing vehicle dimension restrictions as it may reduce some instances of vehicles getting stuck, if the driver only knows their size in metric. How is a German trucker supposed to know whether or not his 4.75 m truck will fit under a 13'6'' bridge?
The German trucker would not have a 4.75 m truck. Under agreed UNECE rules, countries are expected to provide a clearance of at least 4.5 m, except where signposted otherwise. The UK has gone one better by providing a 5.05 m clearance. This is one reason why (IMO) why double-decker buses are not common on the Continent (but double-decker trains are common whereas the smaller British loading gauge does not allow them).
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FleetlinePhil
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by FleetlinePhil »

Vierwielen wrote: Mon Apr 12, 2021 23:15
M4 Cardiff wrote: Sun Apr 11, 2021 23:05 The one area where the process has been started and really needs to be completed as soon as practicable is dual-signing vehicle dimension restrictions as it may reduce some instances of vehicles getting stuck, if the driver only knows their size in metric. How is a German trucker supposed to know whether or not his 4.75 m truck will fit under a 13'6'' bridge?
The German trucker would not have a 4.75 m truck. Under agreed UNECE rules, countries are expected to provide a clearance of at least 4.5 m, except where signposted otherwise. The UK has gone one better by providing a 5.05 m clearance. This is one reason why (IMO) why double-decker buses are not common on the Continent (but double-decker trains are common whereas the smaller British loading gauge does not allow them).
I can't agree with your logic on the point about double-deck buses, I'm afraid. 4.5m is 14'9" if my converter is to be believed, which is already well above the 14'6" that would be expected for a full-height British double-decker. Large parts of the country used to operate with low-height 13'6" as the norm. It is also noticeable that the new British-built double-deckers ordered for Berlin mentioned on another thread recently are actually much lower (at 4.06m 13'4") than the standard British version of the same body.

Returning to the point of the driver only knowing their height in one unit, I could not have given an instant, instinctive conversion of my 13'6" bus to metric had I suddenly been confronted with an unfamiliar bridge signed only in metric units - say the imperial units had been vandalised. Since my teenage bus-enthusiast years, I have known that a 10, 11 or 12 metre vehicle was approximately equivalent to 33, 36 or 40 feet in length, but a height conversion that has to be accurate to the inch? No, I would have to stop and calculate it or seek confirmation from a supervisor. Now clearly if I was travelling abroad, I would have this calculation done in advance and on display in the cab, as any driver of a large vehicle coming to the UK really should do.
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by Having a cuppa »

FleetlinePhil wrote: Tue Apr 13, 2021 11:20
Vierwielen wrote: Mon Apr 12, 2021 23:15
M4 Cardiff wrote: Sun Apr 11, 2021 23:05 The one area where the process has been started and really needs to be completed as soon as practicable is dual-signing vehicle dimension restrictions as it may reduce some instances of vehicles getting stuck, if the driver only knows their size in metric. How is a German trucker supposed to know whether or not his 4.75 m truck will fit under a 13'6'' bridge?
The German trucker would not have a 4.75 m truck. Under agreed UNECE rules, countries are expected to provide a clearance of at least 4.5 m, except where signposted otherwise. The UK has gone one better by providing a 5.05 m clearance. This is one reason why (IMO) why double-decker buses are not common on the Continent (but double-decker trains are common whereas the smaller British loading gauge does not allow them).
I can't agree with your logic on the point about double-deck buses, I'm afraid. 4.5m is 14'9" if my converter is to be believed, which is already well above the 14'6" that would be expected for a full-height British double-decker. Large parts of the country used to operate with low-height 13'6" as the norm. It is also noticeable that the new British-built double-deckers ordered for Berlin mentioned on another thread recently are actually much lower (at 4.06m 13'4") than the standard British version of the same body.

Returning to the point of the driver only knowing their height in one unit, I could not have given an instant, instinctive conversion of my 13'6" bus to metric had I suddenly been confronted with an unfamiliar bridge signed only in metric units - say the imperial units had been vandalised. Since my teenage bus-enthusiast years, I have known that a 10, 11 or 12 metre vehicle was approximately equivalent to 33, 36 or 40 feet in length, but a height conversion that has to be accurate to the inch? No, I would have to stop and calculate it or seek confirmation from a supervisor. Now clearly if I was travelling abroad, I would have this calculation done in advance and on display in the cab, as any driver of a large vehicle coming to the UK really should do.
Surely continental lorry drivers must be familiar with the basic imperial units of length before hand. Lorry drivers already have to have a basic knowledge of the road signage, as well as a million and other things. There is even a handbook which details height restrictions within the UK, in both feet and inches, and metres. Is there any reason foreign lorry drivers can't use that as a reference?
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Vierwielen
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by Vierwielen »

Having a cuppa wrote: Tue Apr 13, 2021 22:51 Surely continental lorry drivers must be familiar with the basic imperial units of length before hand. Lorry drivers already have to have a basic knowledge of the road signage, as well as a million and other things. There is even a handbook which details height restrictions within the UK, in both feet and inches, and metres. Is there any reason foreign lorry drivers can't use that as a reference?
Look at things from the point of view of a French lorry driver. He knows that if he goes to Germany, road signs will be in German, but otherwise he will drive on the same side of the road and the units of measure will be the same. Likewise is he goes to Italy. Likewise if he goes to Spain likewise if he goes to .... (anywhere else on the Continent). However if he goes to the United Kingdom, he will find it to be an exceptional country - full of bloody exceptions.

Matters are worse for say a Spanish driver who normally does a run from Spain to Germany and then when he turns around, he has to take a load to the UK at short notice. Where does he get his information about the exceptions in the UK. For reasons outlined above, an unexpected trip to Poland would be easier.
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by Duncan macknight »

Speaking Personally as someone who lives in the Gaelic signage area, I personally loathe these disgusting signs. They make the sign look cluttered and, at times, difficult to read.

The Whole Purpose of a Roadsign is to convey information as quickly as possible to the driver, Not to show the areas Heritage and History. Keep that for Museums and Textbooks please...
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Chris Bertram
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by Chris Bertram »

Start with motorways - they're the most likely roads to have European freight traffic on them in the first place, and it's a manageable mileage of road to apply the additional information to. Then spread out to the trunk road network, starting with roads leading to ferry ports and possibly container ports. See how it goes from there - the primary network would be next in line, I would have thought. In all cases, the metric distance to be marked with km, with imperial distances left as is. For now, anyway.
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by Jim606 »

One irony is Motorway marker posts used to help pinpoint maintenance and emergency locations are in metric. However, I am not too sure on the exact distance between smart motorway refuge areas. That might still be in imperial at 1.5miles?
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by Vierwielen »

Jim606 wrote: Thu Apr 15, 2021 14:05 One irony is Motorway marker posts used to help pinpoint maintenance and emergency locations are in metric. However, I am not too sure on the exact distance between smart motorway refuge areas. That might still be in imperial at 1.5miles?
The quoted distances between smart motorway refuge areas are probably expressed in metric units if you are talking to an engineer and in imperial units if you are talking to a politician.
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by pjr10th »

I think the conversion to metric on road signs really does need to happen. Most young people are more familiar with metres and yards are only used by us when we start driving.

I think we could starting tomorrow post all signs under 1600 m in metres on new/replaced signage. Maintain miles on >1mi distances but post the kilometres in brackets next to it (or in a patch).

For example -

Hump
50 m

Clearway
for 1400 m

Bends
for 3.5 miles

M1. mi (km)
Milton Keynes 1 (2)
Luton 10 (16)
London 25 (40)

Metres and yards are of course practically the same so there should be no trouble in switching over to m. We already use two measurement units on the road already: miles and yards. These are practically two measurement systems because how many drivers know how many yards are in a mile? So it should be no trouble to switch one of those over to a more internationally recognised measurement system that Brits have been taught in for half a decade, while having dual units for the remainder.

I'd even argue that for the level of precision needed for drivers, metres are superior to work alongside miles than yards. 1609 m vs 1760 yards in a mile. 1600 m in practice, a lot easier to work with to make approximations than 1760. We could designate a metric mile as official distance standard too, set to 1600 m for use in future signage. Even up to 70 mph that's still 112 km/h vs 112.6 km/h.

Convert our road signs to metric by stealth by creating a "new" measurement unit to work with our roads & minds. When the average Brit is finally ready, then we do the change over to km only and km/h.
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by Herned »

There is absolutely no chance of metrication of distances or speed in the foreseeable future. There is no political will, even in the smaller parties, to do it. There is no clamour from the public either. There is also little practical benefit when measuring in whole units to changing over.

Signing bridge heights and widths is a different matter, they need to all be displayed in metric and imperial, as the vast proportion of the workforce has been educated in metric.
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by Kinitawowi »

It's not always just a case of straight up "replacing" or "patching" signs.

The best example I saw is of the junction approach signs on motorways - the 1 mile and 1/2 mile signs. Would these be replaced with 1609m and 804m? Or 1600m and 800m? Or would the really sensible thing to do be to relocate them entirely, to 2km and 1km? Is that cost-effective? Is it even practical at many space-compacted junctions? Etc?

Metrication isn't happening any time soon and hybridisation as a stepping stone is only going to cause confusion.
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by Helvellyn »

Vierwielen wrote: Mon Apr 12, 2021 23:15
M4 Cardiff wrote: Sun Apr 11, 2021 23:05 The one area where the process has been started and really needs to be completed as soon as practicable is dual-signing vehicle dimension restrictions as it may reduce some instances of vehicles getting stuck, if the driver only knows their size in metric. How is a German trucker supposed to know whether or not his 4.75 m truck will fit under a 13'6'' bridge?
The German trucker would not have a 4.75 m truck. Under agreed UNECE rules, countries are expected to provide a clearance of at least 4.5 m, except where signposted otherwise. The UK has gone one better by providing a 5.05 m clearance. This is one reason why (IMO) why double-decker buses are not common on the Continent (but double-decker trains are common whereas the smaller British loading gauge does not allow them).
It shouldn't be hard to check the local requirements and units when you go to another country.
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by Helvellyn »

Vierwielen wrote: Wed Apr 14, 2021 18:48
Having a cuppa wrote: Tue Apr 13, 2021 22:51 Surely continental lorry drivers must be familiar with the basic imperial units of length before hand. Lorry drivers already have to have a basic knowledge of the road signage, as well as a million and other things. There is even a handbook which details height restrictions within the UK, in both feet and inches, and metres. Is there any reason foreign lorry drivers can't use that as a reference?
Look at things from the point of view of a French lorry driver. He knows that if he goes to Germany, road signs will be in German, but otherwise he will drive on the same side of the road and the units of measure will be the same. Likewise is he goes to Italy. Likewise if he goes to Spain likewise if he goes to .... (anywhere else on the Continent). However if he goes to the United Kingdom, he will find it to be an exceptional country - full of bloody exceptions.

Matters are worse for say a Spanish driver who normally does a run from Spain to Germany and then when he turns around, he has to take a load to the UK at short notice. Where does he get his information about the exceptions in the UK. For reasons outlined above, an unexpected trip to Poland would be easier.
That's all stuff that should be a very minor difficulty indeed, and it's not as if all the rules and details and signs are the same in every European country.
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by jnty »

Metrification would only make sense as a European standardisation measure for which there is clearly going to be no UK-wide appetite for decades. You might see it in a heavily devolved or independent Scotland and would almost certainly see it in a united Ireland.

The issues that make switching from yards to metres easy is also the issue that makes it a bit pointless - they are pretty much 1:1 with metres (literally on UK signage, I think?) and if you don't know that for a fact you can quickly work it out instinctively. The fact that many in the UK are familiar with metres and centimetres isn't really relevant to miles - in fact, I'd argue that the majority of the UK is more familiar with miles than kilometres because their main experience with long distances is almost always miles now. (I personally cycle in kilometres but I still drive in miles!)

I sympathise with the feeling that metric signage is probably the right direction in the long run but any concerted effort to switch over is extremely low priority. I think we're more likely to not have signs in 30 years than we are to have signs in metric.
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by jnty »

Kinitawowi wrote: Wed Aug 31, 2022 10:25 It's not always just a case of straight up "replacing" or "patching" signs.

The best example I saw is of the junction approach signs on motorways - the 1 mile and 1/2 mile signs. Would these be replaced with 1609m and 804m? Or 1600m and 800m? Or would the really sensible thing to do be to relocate them entirely, to 2km and 1km? Is that cost-effective? Is it even practical at many space-compacted junctions? Etc?

Metrication isn't happening any time soon and hybridisation as a stepping stone is only going to cause confusion.
1mi signs would surely be replaced with 1.5km signs, and 1/2mi with either 800m or 1km. That might even be more accurate for many of them - have you ever seen a 9/10mi or 3/5mi warning sign? Many mileage signs are well off their alleged distance due to necessity and rounding and there would be little problem with doing the same for kilometres. Of course, the slightly confusing 2/3mi signs which sometimes pop up could happily be replaced with 1km.

If you ever did to a phased transition, restricting the change to the motorway network initially would be a reasonable place to start and provide 'consistent inconsistency' to the motorist. Again though, I think we're more likely to leave the motorways to driverless cars than we are to spend money updating their signage.
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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by KeithW »

the cheesecake man wrote: Mon Apr 12, 2021 13:37 They could find out before visiting a country they know has imperial signs, just like they'd make sure they know which side of the road we drive on etc. Or they could stop and phone their depot if they're not sure?
Many low bridges on major routes are dual signed
Albert Railway Bridge Middlesbrough
https://www.google.co.uk/maps/@54.57885 ... 8192?hl=en

In any case how hard is it to stick a reminder in the corner of the windscreen or on the dashboard ?

For a high tech solution you can get it all in one on a truck sat nav, feed in the vehicle height and it will choose a suitable route to avoid such hazards as well as roads that are too narrow for the vehicle.

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Re: Possible hybrid 'Imperial & Metric' distance signage on some selected roads

Post by Vierwielen »

jnty wrote: Wed Aug 31, 2022 10:45
Kinitawowi wrote: Wed Aug 31, 2022 10:25 It's not always just a case of straight up "replacing" or "patching" signs.

The best example I saw is of the junction approach signs on motorways - the 1 mile and 1/2 mile signs. Would these be replaced with 1609m and 804m? Or 1600m and 800m? Or would the really sensible thing to do be to relocate them entirely, to 2km and 1km? Is that cost-effective? Is it even practical at many space-compacted junctions? Etc?

Metrication isn't happening any time soon and hybridisation as a stepping stone is only going to cause confusion.
1mi signs would surely be replaced with 1.5km signs, and 1/2mi with either 800m or 1km. That might even be more accurate for many of them - have you ever seen a 9/10mi or 3/5mi warning sign? Many mileage signs are well off their alleged distance due to necessity and rounding and there would be little problem with doing the same for kilometres. Of course, the slightly confusing 2/3mi signs which sometimes pop up could happily be replaced with 1km.

If you ever did to a phased transition, restricting the change to the motorway network initially would be a reasonable place to start and provide 'consistent inconsistency' to the motorist. Again though, I think we're more likely to leave the motorways to driverless cars than we are to spend money updating their signage.
The norm that I have seen on the continent is that distances to off-ramps are usually expressed in terms of hundreds of metres rather than fractions of a kilometre. For example, this sign has a distance of 900 metres.
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