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

[Jim606]

Whilst we’ve discussed metrification before, I think it was generally agreed that it will never happen in the foreseeable future. However, I remembered the idea of introducing some kind of hybrid imperial / metric signage on particular roads such as the M20? We have bilingual signage in Scotland & Wales so, why not bi-measurement distance signage? Particularly, on roads which connect to exit / entry points to the UK (Channel Tunnel & certain ports).

Which ones would qualify though and how far inland would the dual distance signage go? I would suggest that miles still come first with kilometres in brackets afterwards? The M20 is the obvious candidate, perhaps to the M25? The A63 near Hull & the A120 from Harwich could also see some metrification? Are there any examples from elsewhere? Any other thoughts, political / brexit issues aside?

[jervi]

I don't think we will ever see distances in KM, even around ports or on the SRN. What would the benefit of having KM displayed as well as Miles?
Nowadays pretty much everyone uses a satnav, especially when travelling routes that you haven't done before. So people from other countries can have KM used and the measurement on their satnavs if they really can't handle Miles.
Also distances are not really shown on signs anymore, apart from RCSs and ADSs on DCs/motorways its hard to find a directional sign showing distance. Fingerpost signs do, but those are to reflect our heritage so will never show KM.

We would be better off showing usual travel time to destination than showing KMs, that would have marginal benefits but unlikely to be justified for various reasons.

[Was92now625]

Particularly, on roads which connect to exit / entry points to the UK (Channel Tunnel & certain ports).
....
The M20 is the obvious candidate, perhaps to the M25?

So do you mean on the M20 e.g. London 30 miles 48 km

or do you mean distances to Paris/Brussels etc (and then whether or not to include the non-road bit) ?

[Jim606]

Particularly, on roads which connect to exit / entry points to the UK (Channel Tunnel & certain ports).
....
The M20 is the obvious candidate, perhaps to the M25?

So do you mean on the M20 e.g. London 30 miles 48 km

or do you mean distances to Paris/Brussels etc (and then whether or not to include the non-road bit) ?

Well it's an idea. Whilst most Sabre folk generally agree that we'll never see km's in the UK, I do believe there could be limited use in certain circumstances i.e. approaching the Channel Tunnel. I am sure many of the existing signs could have the km's added? I guess it depends upon the percentage of continental drivers using a particular route and political will or complete lack of it! However, we now refer to many new build road projects in km's. The Stonehenge Tunnel at 3.3km is an obvious example. Perhaps, the use of km's makes it seem longer?

[Vierwielen]

In my view, having dual units would be a disaster. They would clutter up the sign with unnecessary detail. If we are to change over to metric units, the approach that I would take in respect of distances is to replace imperial road signs with metric road signs as the imperial signs reach the ends of their useful lives. In parallel I would initiate a program of installing new route confirmation signs 50 metres or so beyond existing signs on trunk road starting with the busiest roads (ie M25, M1 etc) and remove the imperial road signs on those roads once they reach the ends of their lives. The rate at which signs on trunk roads are introduced would be determined by the budget allowed. At the same time driver location signs would be publicised and services be allocated numbers Sxxx where xxx corresponds to the kilometre part of the DLS closest to the services.

[Jim606]

In my view, having dual units would be a disaster. They would clutter up the sign with unnecessary detail. If we are to change over to metric units, the approach that I would take in respect of distances is to replace imperial road signs with metric road signs as the imperial signs reach the ends of their useful lives. In parallel I would initiate a program of installing new route confirmation signs 50 metres or so beyond existing signs on trunk road starting with the busiest roads (ie M25, M1 etc) and remove the imperial road signs on those roads once they reach the ends of their lives. The rate at which signs on trunk roads are introduced would be determined by the budget allowed. At the same time driver location signs would be publicised and services be allocated numbers Sxxx where xxx corresponds to the kilometre part of the DLS closest to the services.

Yes, metrification raises many issues, i.e. whether the country could go for a total or more of a piecemeal change? Of course money is another issue along with the fact many people have an affinity with miles and imperial units. However, metric measurements are a international standard and they are certainly used in the UK in regards to many new road projects. As mentioned before, I don't see modern road contractors actually measuring anything in yards and miles when it comes to the detailed plans? Yet, the signage on the finished product is still in 'Imperial Units'.

Surely, it would make sense to trial a hybrid system on a specific road. i.e. have the respective minister or highway authority issue a directive to do so. One example could be the A63 Castle Street project in Hull. This scheme links direct to the port and is used by many continental drivers. The scheme could act as a trial. It just needs the political will.

[Jim606]

Found these opposing websites;
https://metricviews.org.uk/2017/11/11/u ... in-the-uk/ & http://bwma.org.uk/

From Metric Views;
In the UK, miles are generally preferred to kilometres, especially in the non-specialist media. This is probably a consequence of the continued use of miles on road traffic signs, and contrasts with the widespread use of metric measures for shorter distances. However, we are accustomed to using the kilometre in many different contexts in the UK, and this article looks at some of them.

Modern tram and light rail systems
Modern British tram and railway systems such as the Docklands Light Railway (DLR) and the Croydon tram network are entirely metric and use kilometres. As the metric ERTMS signalling system is rolled out over the next 20 years, the use of kilometres will increase on British railways (see https://metricviews.org.uk/2014/08/metr ... l-network/ for more details).
Diamond-shaped speed signs for tram drivers use a white background with a black border. The black digits that appear on these signs represent tram speed limits in kilometres per hour. These signs are only intended for tram drivers.

Ordnance Survey maps
Ordnance Survey maps use a kilometre-based grid and have used metric scales for over forty years.

Commercial road atlases
Commercial road atlases use kilometre-based gridlines and dual scales. Typically, the scales use both miles and kilometres. Despite the fact that the Ordnance Survey is exclusively metric and is the basis for commercial map makers, dual-measurement road atlases are undoubtedly strongly influenced by the continued use of miles on British roads.

High Speed 1
Britain’s only high speed line, HS1, from London St Pancras to Folkestone, has speed limit signs in km/h (shown as “KMH”).

Tachographs and speed limiters for large vehicles
Tachographs use kilometres to record the travel distances for big vehicles. The speed limiters used for big vehicles are based on kilometres per hour, which is incompatible with official speed limit signs on British roads.

Motorcycle tests
Motorcycle tests include an emergency stop at 50 km/h, which is the standard speed limit for urban areas throughout Europe, except the UK of course. You can find out more about British motorcycle tests in a previous MV article at https://metricviews.org.uk/2010/04/dft- ... %99-money/.

[Helvellyn]

Change for the sake of change. Better just to drop the whole attempt at metrification behind the scenes really and just stick with miles from start to finish.

[Gareth Thomas]

I can’t see it working - if a lorry driver is only looking at the km distances along the M20 in Kent, but then they cross the border into Surrey or Essex and the km distances suddenly disappear, that could cause confusion. Or people would realise and just continue to look at the miles, which would make the km distances pointless.

If metrification were ever to come in, a “Big Bang” switchover would probably be better.

[Jim606]

I can’t see it working - if a lorry driver is only looking at the km distances along the M20 in Kent, but then they cross the border into Surrey or Essex and the km distances suddenly disappear, that could cause confusion. Or people would realise and just continue to look at the miles, which would make the km distances pointless. If metrification were ever to come in, a “Big Bang” switchover would probably be better.

Yes, a big bang would be better. But, there is no political will or money, so, it isn't likely to ever happen any time soon. However, the UK can't keep running away from km's for ever. I still think a small test scheme like the A63 Castle Street, in Hull might work? Otherwise, you might have to km a whole route?

[Chris Bertram]

Found these opposing websites;
https://metricviews.org.uk/2017/11/11/u ... in-the-uk/ & http://bwma.org.uk/

From Metric Views;
In the UK, miles are generally preferred to kilometres, especially in the non-specialist media. This is probably a consequence of the continued use of miles on road traffic signs, and contrasts with the widespread use of metric measures for shorter distances. However, we are accustomed to using the kilometre in many different contexts in the UK, and this article looks at some of them.

Modern tram and light rail systems
Modern British tram and railway systems such as the Docklands Light Railway (DLR) and the Croydon tram network are entirely metric and use kilometres. As the metric ERTMS signalling system is rolled out over the next 20 years, the use of kilometres will increase on British railways (see https://metricviews.org.uk/2014/08/metr ... l-network/ for more details).
Diamond-shaped speed signs for tram drivers use a white background with a black border. The black digits that appear on these signs represent tram speed limits in kilometres per hour. These signs are only intended for tram drivers.

Ordnance Survey maps
Ordnance Survey maps use a kilometre-based grid and have used metric scales for over forty years.

Commercial road atlases
Commercial road atlases use kilometre-based gridlines and dual scales. Typically, the scales use both miles and kilometres. Despite the fact that the Ordnance Survey is exclusively metric and is the basis for commercial map makers, dual-measurement road atlases are undoubtedly strongly influenced by the continued use of miles on British roads.

High Speed 1
Britain’s only high speed line, HS1, from London St Pancras to Folkestone, has speed limit signs in km/h (shown as “KMH”).

Tachographs and speed limiters for large vehicles
Tachographs use kilometres to record the travel distances for big vehicles. The speed limiters used for big vehicles are based on kilometres per hour, which is incompatible with official speed limit signs on British roads.

Motorcycle tests
Motorcycle tests include an emergency stop at 50 km/h, which is the standard speed limit for urban areas throughout Europe, except the UK of course. You can find out more about British motorcycle tests in a previous MV article at https://metricviews.org.uk/2010/04/dft- ... %99-money/.

The London in Underground is an odd hybrid. Its signed speed limits are in mph, but track distances are metric, usually calculated to the nearest 10mm from a datum point at Ongar, which is no longer on the Tube network. This suggests that engineering measurements are metric, and as automatic operation increases across the network (the Victoria Line has been automatic since opening in 1967, and the Jubilee and Central Lines are also now automatic) signed speeds will become increasingly irrelevant.

[Bryn666]

Change for the sake of change. Better just to drop the whole attempt at metrification behind the scenes really and just stick with miles from start to finish.

For most things we do work in metric, but I can't see the benefit in changing every single road sign...

UNLESS, we did it in conjunction with sorting out our 100 year old, and no longer fit for purpose, A and B road system

[M4 Cardiff]

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?

[Having a cuppa]

The only possibility of hybrid 'Imperial & Metric' distances appearing is on Route Confirmation Signs, similar to this American sign: https://metricpioneer.com/effort/metric ... road-sign/ Even still we would run into some issues, for instance would you sign "Example City 1 1/2 mile" as "Example City 1 1/2 mile 2.4 km" or "Example City 1 1/2 mile 2 1/2 km"? Dual units on other signage would make it feel cluttered, for instance look at Welsh signage where "150 yards" and "150 llath" appears on the same sign. At least with Welsh signs, they both refer to the same units. In my opinion, we should keep using miles and yards and refine the current system. Instead of signing a distance of 400 metres as 400 yds, sign it as 440 yds or 1/4 mile. The DfT conversions between metric and imperial units are not standardized and at times, inaccurate beyond a reasonable tolerance. Another improvement which should be made is an improved National Speed Limit information sign. Look at this: https://www.google.com/search?q=uk+nati ... 3WCoRtwNbM There isn't even a conversion between 30 mph and 50 km/h, with 30 mph being our urban speed limit. I would be ok with implementation of solely dual unit Route Confirmation Signs on select routes, on the condition the Metric Crusaders stop whining.

[Enceladus]

Whilst a dual metric/imperial signage system on key trunk routes that connect with the Channel ports sounds very useful as a concept, in practice there would be several problems, outlined above by the other posters. In any case, with Brexit I don’t think metrication of British road signs will be happening any time soon. It would be political suicide.

In Ireland we changed to metric for distances when the new National Primary/Secondary/Regional classification system was introduced in the 1970s and the then new signage was rolled out, but the speed limits remained in miles per hour until 2003 - and the older black and white fingerposts that the tourists love were in miles. Rather confusing for those not used to it!

[Ruperts Trooper]

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?

How hard is it? I've have a sticker on my dashboard reminding me of the dimensions of my caravan outfit in both Imperial and metric - it's not like a trucker from European mainland strays into the UK by mistake or because of a diversion. Do Irish truckers have an issue in NI?

[WHBM]

Do Irish truckers have an issue in NI?

Quite possibly. Vehicles supplied in the UK all have speedos showing both mph and kmph. In Ireland, only the latter.

Likewise there are suggestions here for dual signage on routes to the Channel ports. No prospect of there being anything reciprocal, with some French signage towards Calais also showing miles.

[solocle]

There is a rather lovely road sign that's solely in French near me...

[A303Chris]

There is a rather lovely road sign that's solely in French near me...
F965FA67-F407-4138-B438-623F956032AC.jpeg

Where is that?

[solocle]

There is a rather lovely road sign that's solely in French near me...
F965FA67-F407-4138-B438-623F956032AC.jpeg

Where is that?

A350 Hole's Bay Road heading out of Poole. It makes sense as it's the primary route away from the channel ports. If you go through Hamworthy instead, there's a multilingual "drive on the left" sign.