Should the NSL sign be abandoned?

The study of British and Irish roads - their construction, numbering, history, mapping, past and future official roads proposals and general roads musings.

There is a separate forum for Street Furniture (traffic lights, street lights, road signs etc).

Registered users get access to other forums including discussions about other forms of transport, driving, fantasy roads and wishlists, and roads quizzes.

Moderator: Site Management Team

User avatar
Keiji
Member
Posts: 1222
Joined: Mon Jan 25, 2010 18:13
Location: Torquay, Devon
Contact:

Should the NSL sign be abandoned?

Post by Keiji »

Patrick's thread ("NSL Logic") reminded me of this question that's been bugging me lately.

Originally (correct me if I'm wrong!! I was not around then :) ) NSL literally meant that a road had no speed limit, and then in the time of the Oil Crisis, the National Speed Limit of 60 and 70 was introduced. It made sense to leave the signs alone as the alternative would be to replace every such sign in the country to great expense - and be expecting to replace them all back again later as it was originally intended to be a temporary measure.

By now we're very much aware that it's become one of those "permanent temporary measures", and it can be argued that the existence of the mere concept of NSL causes more harm than good. It leads to the ridiculous situation where single-carriageway roads with frequent bits of short D1 for e.g. turnings on them either have frequent alternating 60/NSL/60/NSL signs or get reduced to 50 simply to avoid that, and it also means we get unlawful 60's showing up when NSL dual carriageway becomes single carriageway because some drivers don't realise the limit reduced implicitly and need to be reminded.

When a road becomes urban or rural and no other speed limits apply we already have 30 and NSL terminals, generally with no repeaters required because you can tell from the context of the road (i.e. from the presence or absence of street lighting). This works just fine. Why shouldn't we do the same where a single carriageway becomes dual or vice versa? Put 70 and 60 terminals at these points - and similarly repeaters aren't required because you can tell from the context (i.e. whether it is a single or dual carriageway).

This would allow long stretches of road to stay at 60 whether or not they have bits of dual on them, and would make it abundantly clear at what point the limit rises to 70 or reduces to 60 at the start/end of a dual carriageway where this is otherwise ambiguous. It'd also make it possible in the future to have another go at that officially-80-on-a-motorway-trial where the confusion over the NSL sign was one prohibitive factor ;) And it'd mean consistency with things like Scottish motorways and Special Roads that have explicit 70 signs on them (are there any of the latter left now?).

It would mean that 70/60 terminal signs would have to be installed at the start/end of every existing NSL dual carriageway where no current sign exists, of course. Otherwise, it would not be possible to legislate that "now when a 60 single carriageway becomes dual without a sign, it's still a 60". I'd also argue that numeric terminal signs be added next to start/end of motorway signs where there is not already a lower limit in place - perhaps a nice standard combined design could be invented for this. However, while no new NSL signs would be installed, existing NSL terminal/repeater signs could stay in place until removed as part of regular maintenance - they would simply carry the meaning of "60 on a single carriageway or 70 on a dual", as they do now.

As for things that aren't cars/motorbikes and have to use a lower speed limit depending on the road type anyway, this could be changed to be based on a combination of vehicle type and signed speed limit, rather than vehicle type and road type as present. (Officially raising the standard motorway limit to 80 as hinted above would then deal with the case of motorway limits being different to non-motorway dual carriageway limits for some vehicle types... :stir: )

After writing this, I do feel that transitioning this would be harder than I originally thought (in terms of how many places there are where new signs would have to be put up), for not too much gain given how familiar the majority of drivers are with the status quo - but I suppose it's still potentially worthy of discussion. Also, how do other countries deal with this? I know RoI blanket replaced all its speed limit signs when it switched to kmph - does it still have a concept of NSL, or did it take the opportunity to use only numeric signs and do away with any concept of "NSL" it may have had before, or did it never have such a concept in the first place? Do most (major) countries have a similar situation to us, where implicit changes are common, or do they mostly already explicitly, numerically sign every road speed limit change so as to avoid implicit changes? I know France has a silly rule about the limit being 20 kmph lower when it's raining (how wet does it have to be to be "raining"? how long does it have to be "raining" for? how quickly do you have to slow down if you're doing the limit and a freak shower hits you?), but I'm not talking about those kinds of implicit rules here, rather only implicit rules that make the speed limit change based on entering a different road type.
User avatar
c2R
SABRE Wiki admin
Posts: 11162
Joined: Fri Jul 05, 2002 11:01

Re: Should the NSL sign be abandoned?

Post by c2R »

The problem with a blanket move to signed speed limits is the implication that it has been assessed and found safe to travel at that speed on that section of road. Ireland has reintroduced the rural derestriction sign on some roads because of this, where it would be patently absurd to do 80kmh.
Is there a road improvement project going on near you? Help us to document it on the SABRE Wiki - help is available in the Digest forum.
Have you browsed SABRE Maps recently? Get involved! - see our guide to scanning and stitching maps
User avatar
Gareth
Member
Posts: 1729
Joined: Thu Jul 28, 2005 19:16
Location: Liverpool
Contact:

Re: Should the NSL sign be abandoned?

Post by Gareth »

I prefer the responsibility the derestriction sign puts on the motorist to judge the practical speed of the road. People tend to see posted speed limits as a target rather than an absolute maximum.
ais523
Member
Posts: 1139
Joined: Tue Sep 08, 2015 19:52
Location: Birmingham

Re: Should the NSL sign be abandoned?

Post by ais523 »

There's also a possibility that we might want or need to change the value of NSL again. (With the shortage of oil and thus petroi/diesel caused by current geopolitical events, a reduction of NSL to 60/60 or even 50/60 isn't even that implausible.) Having the NSL signs say NSL, rather than an explicit number, makes that sort of change much easier to make.
User avatar
jervi
Member
Posts: 1596
Joined: Thu Aug 17, 2017 16:29
Location: West Sussex

Re: Should the NSL sign be abandoned?

Post by jervi »

To be perfectly honest, it doesn't need to change. Changing the whole country over to a new system would take many years and cost a lot of money, and for something that in general isn't causing issues. Also looking ahead, will we need speed limit signs in 25-30 years time? Cars for the past 10+ years have been showing the speed limit on their displays, most cars today can do it. In the coming month all new cars will have a speed warning systems installed, then give it 25 years for all current cars to be retired and heypresto speed limit signs are now redundant.
User avatar
KeithW
Member
Posts: 19201
Joined: Thu Dec 04, 2014 13:25
Location: Marton-In-Cleveland North Yorks

Re: Should the NSL sign be abandoned?

Post by KeithW »

In a word No, for one thing it means you have reached the end of a specific speed limit and for another putting up new signs would cost a lot of money and achieve nothing of substance.

According to the DFT the statistics are this

2,300 miles of motorway
29,400 miles of ‘A’ road
18,800 miles of ‘B’ road
53,400 miles of ‘C’ road
142,700 miles of ‘U’ road

Properly assessing the correct maximum speed would be a huge exercise and I doubt it would achieve anything of substance. On NSL roads good drivers limit themselves and bad drivers end up in the ditch if they are lucky and in hospital or the morgue if not.
User avatar
KeithW
Member
Posts: 19201
Joined: Thu Dec 04, 2014 13:25
Location: Marton-In-Cleveland North Yorks

Re: Should the NSL sign be abandoned?

Post by KeithW »

jervi wrote: Fri Jun 24, 2022 19:20 To be perfectly honest, it doesn't need to change. Changing the whole country over to a new system would take many years and cost a lot of money, and for something that in general isn't causing issues. Also looking ahead, will we need speed limit signs in 25-30 years time? Cars for the past 10+ years have been showing the speed limit on their displays, most cars today can do it. In the coming month all new cars will have a speed warning systems installed, then give it 25 years for all current cars to be retired and heypresto speed limit signs are now redundant.
There are plenty of vintage and veteran cars still around and not all current cars have integrated GPS receivers linked to a speed limiter. Then as a long time sofware engineer and sceptic I have visions of the Speed Control Centre or satellite failing and the whole country grinding to a halt. Lots of luck fitting such a system to a light motorcycle or moped.

My adage always has been and remains - simple is best.
User avatar
JohnnyMo
Member
Posts: 6982
Joined: Wed Jun 04, 2003 13:56
Location: Letchworth, Herts, England

Re: Should the NSL sign be abandoned?

Post by JohnnyMo »

Keiji wrote: Fri Jun 24, 2022 18:17 Patrick's thread ("NSL Logic") reminded me of this question that's been bugging me lately.

Originally (correct me if I'm wrong!! I was not around then :) ) NSL literally meant that a road had no speed limit, and then in the time of the Oil Crisis, the National Speed Limit of 60 and 70 was introduced. It made sense to leave the signs alone as the alternative would be to replace every such sign in the country to great expense - and be expecting to replace them all back again later as it was originally intended to be a temporary measure.
...
The literal meaning was end of [speed] restriction, practically this was the same thing originally no speed limit. You can see the same principle on some End of No Overtaking signs in other countries.
I am not sure if there was even really a plan to reinstate unlimited speed, as the reason for the trial was car doing over 150mph.

The Oil Crisis was 9 years later with the speed limits were temporarily reduced.
“The simple step of a courageous individual is not to take part in the lie" - Aleksandr I. Solzhenitsyn
Johnny Mo
User avatar
Keiji
Member
Posts: 1222
Joined: Mon Jan 25, 2010 18:13
Location: Torquay, Devon
Contact:

Re: Should the NSL sign be abandoned?

Post by Keiji »

c2R wrote: Fri Jun 24, 2022 18:55 The problem with a blanket move to signed speed limits is the implication that it has been assessed and found safe to travel at that speed on that section of road. Ireland has reintroduced the rural derestriction sign on some roads because of this, where it would be patently absurd to do 80kmh.
Gareth wrote: Fri Jun 24, 2022 19:12 I prefer the responsibility the derestriction sign puts on the motorist to judge the practical speed of the road. People tend to see posted speed limits as a target rather than an absolute maximum.
Well doh, I feel rather silly now!

Yes, I'd somehow missed that entire side of things. The NSL sign is very useful for that purpose.
ais523 wrote: Fri Jun 24, 2022 19:16 There's also a possibility that we might want or need to change the value of NSL again. (With the shortage of oil and thus petroi/diesel caused by current geopolitical events, a reduction of NSL to 60/60 or even 50/60 isn't even that implausible.) Having the NSL signs say NSL, rather than an explicit number, makes that sort of change much easier to make.
Indeed, and this also occurred to me in the opposite direction when I was writing about the motorway-80 idea: it'd be one thing to just say "NSL on a motorway is now 80", another thing altogether to replace signs at every entrance.

Perhaps every speed limit sign should be replaced with a VSL sign instead? :D
User avatar
Ruperts Trooper
Member
Posts: 12031
Joined: Sun Jun 17, 2012 13:43
Location: Huntingdonshire originally, but now Staffordshire

Re: Should the NSL sign be abandoned?

Post by Ruperts Trooper »

JohnnyMo wrote: Fri Jun 24, 2022 20:12 I am not sure if there was even really a plan to reinstate unlimited speed, as the reason for the trial was car doing over 150mph.
That urban myth won't go away - the Le Mans car tests were during a Conservative government - the limit was introduced 3 years later under a Labour government - Barbara Castle, Minister for Transport when the limit was introduced, subsequently denied that race car testing influenced her decision https://www.autocar.co.uk/car-news/moto ... 1-motorway
Lifelong motorhead
User avatar
JohnnyMo
Member
Posts: 6982
Joined: Wed Jun 04, 2003 13:56
Location: Letchworth, Herts, England

Re: Should the NSL sign be abandoned?

Post by JohnnyMo »

Ruperts Trooper wrote: Fri Jun 24, 2022 20:31
JohnnyMo wrote: Fri Jun 24, 2022 20:12 I am not sure if there was even really a plan to reinstate unlimited speed, as the reason for the trial was car doing over 150mph.
That urban myth won't go away - the Le Mans car tests were during a Conservative government - the limit was introduced 3 years later under a Labour government - Barbara Castle, Minister for Transport when the limit was introduced, subsequently denied that race car testing influenced her decision https://www.autocar.co.uk/car-news/moto ... 1-motorway
Production cars such as the e-type Jag had a claimed top speed of 150mph. A show off Slone ranger at even 140 is probably more dangerous than a professional racing driver at 180.
Midland Red were producing coaches with a top speed about 80. These were mixing with lorries who would struggle to get upto 50, probably less on a hill.
“The simple step of a courageous individual is not to take part in the lie" - Aleksandr I. Solzhenitsyn
Johnny Mo
User avatar
Chris5156
Deputy Treasurer
Posts: 16908
Joined: Thu Sep 06, 2001 21:50
Location: Hampshire
Contact:

Re: Should the NSL sign be abandoned?

Post by Chris5156 »

JohnnyMo wrote: Fri Jun 24, 2022 21:02
Ruperts Trooper wrote: Fri Jun 24, 2022 20:31
JohnnyMo wrote: Fri Jun 24, 2022 20:12 I am not sure if there was even really a plan to reinstate unlimited speed, as the reason for the trial was car doing over 150mph.
That urban myth won't go away - the Le Mans car tests were during a Conservative government - the limit was introduced 3 years later under a Labour government - Barbara Castle, Minister for Transport when the limit was introduced, subsequently denied that race car testing influenced her decision https://www.autocar.co.uk/car-news/moto ... 1-motorway
Production cars such as the e-type Jag had a claimed top speed of 150mph. A show off Slone ranger at even 140 is probably more dangerous than a professional racing driver at 180.
Midland Red were producing coaches with a top speed about 80. These were mixing with lorries who would struggle to get upto 50, probably less on a hill.
All of which is true, but it's not the reason the blanket 70mph speed limit was first brought in. It was a response to repeated pile-ups in foggy weather on the M1 and other motorways, and was part of a package of measures that included the Motorwarn temporary roadside signals and improved traffic bulletins on the radio.
User avatar
Bryn666
Elected Committee Member
Posts: 35754
Joined: Thu Jun 20, 2002 20:54
Contact:

Re: Should the NSL sign be abandoned?

Post by Bryn666 »

Chris5156 wrote: Fri Jun 24, 2022 22:20
JohnnyMo wrote: Fri Jun 24, 2022 21:02
Ruperts Trooper wrote: Fri Jun 24, 2022 20:31

That urban myth won't go away - the Le Mans car tests were during a Conservative government - the limit was introduced 3 years later under a Labour government - Barbara Castle, Minister for Transport when the limit was introduced, subsequently denied that race car testing influenced her decision https://www.autocar.co.uk/car-news/moto ... 1-motorway
Production cars such as the e-type Jag had a claimed top speed of 150mph. A show off Slone ranger at even 140 is probably more dangerous than a professional racing driver at 180.
Midland Red were producing coaches with a top speed about 80. These were mixing with lorries who would struggle to get upto 50, probably less on a hill.
All of which is true, but it's not the reason the blanket 70mph speed limit was first brought in. It was a response to repeated pile-ups in foggy weather on the M1 and other motorways, and was part of a package of measures that included the Motorwarn temporary roadside signals and improved traffic bulletins on the radio.
The myth came about because the Daily Mirror had a front-page about the AC Cobra doing 185 along the M1 in 1964. The 70 limit was resisted by government until the fog deaths rolled in during the peak of road deaths in 1966 (7,985 people died on the roads).

James Drake, incidentally, wrote a lengthy paper insisting motorways had speed limits. He had not been impressed with the low standard German Autobahns with cobbled slip roads and no hard shoulders being a do what you please environment and pointed out our design speed here has always been 75 mph.
Bryn
Terminally cynical, unimpressed, and nearly Middle Age already.
She said life was like a motorway; dull, grey, and long.

Blog - https://showmeasign.online/
X - https://twitter.com/ShowMeASignBryn
YouTube - https://www.youtube.com/@BrynBuck
User avatar
JohnnyMo
Member
Posts: 6982
Joined: Wed Jun 04, 2003 13:56
Location: Letchworth, Herts, England

Re: Should the NSL sign be abandoned?

Post by JohnnyMo »

Also remember it was not just the motorways which were unrestricted, roads like the A1 and even urban roads like the North Circular also had no speed limit.
“The simple step of a courageous individual is not to take part in the lie" - Aleksandr I. Solzhenitsyn
Johnny Mo
User avatar
FosseWay
Assistant Site Manager
Posts: 19621
Joined: Thu Feb 23, 2006 22:26
Location: Gothenburg, Sweden

Re: Should the NSL sign be abandoned?

Post by FosseWay »

c2R wrote: Fri Jun 24, 2022 18:55 The problem with a blanket move to signed speed limits is the implication that it has been assessed and found safe to travel at that speed on that section of road. Ireland has reintroduced the rural derestriction sign on some roads because of this, where it would be patently absurd to do 80kmh.
This is the obvious reason to keep the NSL sign.

From the point of view of avoiding extra signage clutter while still making it clear to drivers what the limit is, it doesn't really matter whether you have an NSL sign or 60/70. Where reform is more needed IMO is in the areas covered by the "urban default limit", given that (a) getting people to stick to the limit is more important there, (b) misunderstandings regarding streetlighting or actual improper absence of lights means that the system "fails to unsafe" - i.e. apparently tells people they can drive faster than they should, rather than the opposite, and (c) there are now in effect two urban default limits, 30 and 20, with no clear way of distinguishing them without plastering one or the other with a load of signage.

On the other hand, I think we should be a bit less hidebound about signage rules. For example, I see no reason not to use 30 repeaters on a default 30 stretch if there is a known problem with people driving faster than that. On a related note, I would also want to investigate the usefulness of posting some roads as 60 and others as NSL, even though NSL in these cases means 60. This would become even more useful if NSL were reduced to 50. Roads which have been actively assessed and given a speed limit as a result of that assessment would have a numerical speed limit, while those subject to a general default would have the NSL sign. The former would tell drivers that in general on that road, in ideal weather and traffic conditions, it is broadly safe to drive up to the posted limit. The latter would tell them that their speed is entirely up to them, and anything from zero to NSL may be appropriate regardless of dynamic changes like weather and traffic.

This is something I notice in Sweden a lot. Here, the NSL sign was abolished in 1967 when blanket speed limits in rural areas were introduced. Before that, as historically in the UK, it meant "no speed limit". The equivalent of default NSL here is 70 km/h on single carriageway roads, but a lot of major roads are signed with higher limits. On those higher limited roads there are stretches around junctions where the limit is reduced to 70. There are also "major" roads with a defined rather than default 70 limit. In short, there are a lot of places where 70 is used as an intentional, assessed limit but there is no way of telling these apart from the default. As in the UK, the presumption is that you can drive up to the limit in ideal conditions on roads with a tailored limit, but NSL says nothing about the practicality of the posted limit.
Did you know there's more to SABRE than just the Forums?
Add your roads knowledge to the SABRE Wiki today!
Have you browsed SABRE Maps recently? Try getting involved!
User avatar
KeithW
Member
Posts: 19201
Joined: Thu Dec 04, 2014 13:25
Location: Marton-In-Cleveland North Yorks

Re: Should the NSL sign be abandoned?

Post by KeithW »

JohnnyMo wrote: Fri Jun 24, 2022 21:02 Production cars such as the e-type Jag had a claimed top speed of 150mph. A show off Slone ranger at even 140 is probably more dangerous than a professional racing driver at 180.
Midland Red were producing coaches with a top speed about 80. These were mixing with lorries who would struggle to get upto 50, probably less on a hill.
Yes but they were the exception not the rule.

Take a look at the max speed of most cars on the road in the mid 1960's
Ford 105E Anglia - 73.8 mph
Morris 1000 - 73 mph
Vauxhall Victor - 81 mph
Austin Cambridge A60 - 80mph

These cars had a realistic cruising speed 10 mph lower than the top speed and were extraordinarily unsafe in a crash, no crumple zone, no seatbelts, it was quite normal for even urban crashes to produce fatalities. Most cars still had drum brakes and no servo, anchor up at 70 on a motorway and by the time you stopped you were well into brake fade. The reality is that unless you were up at the crack of dawn the chances of being able to anything above 70 on the D2(M) M1 south of the M45 was not good.

The major problem of the day was the drivers mindset. Most simply didnt realise that a collision at 70 mph in the cars of the day would almost inevitably result in fatalities. In the early 1970's my cousin had his own garage and recovery vehicle and I used to help him out on weekends and saw some horrific accidents. The one that remains in my head to this day was in 1972 when we were called to an accident on the A19 near Thirsk. An MGB tourer had gone under the rear of an HGV and the driver had been decapitated, we found his head in a ditch. There were no under run bars on HGV's at that time. Both vehicles were only lightly damaged.

On more that one occasion in that era I drove past an accident scene where there were crumpled cars dragged on to the hard shoulders, some with tarpaulins over them which generally meant there was a body inside. The priority then was reopening the motorway before another accident happened in the queue.
User avatar
JohnnyMo
Member
Posts: 6982
Joined: Wed Jun 04, 2003 13:56
Location: Letchworth, Herts, England

Re: Should the NSL sign be abandoned?

Post by JohnnyMo »

KeithW wrote: Sat Jun 25, 2022 12:45
JohnnyMo wrote: Fri Jun 24, 2022 21:02 Production cars such as the e-type Jag had a claimed top speed of 150mph. A show off Slone ranger at even 140 is probably more dangerous than a professional racing driver at 180.
Midland Red were producing coaches with a top speed about 80. These were mixing with lorries who would struggle to get upto 50, probably less on a hill.
Yes but they were the exception not the rule.

Take a look at the max speed of most cars on the road in the mid 1960's
Ford 105E Anglia - 73.8 mph
Morris 1000 - 73 mph
Vauxhall Victor - 81 mph
Austin Cambridge A60 - 80mph

These cars had a realistic cruising speed 10 mph lower than the top speed and were extraordinarily unsafe in a crash, ...
That is my point, they would approached other road used in excess of 70mph, maybe in some cases close to 100mph.
“The simple step of a courageous individual is not to take part in the lie" - Aleksandr I. Solzhenitsyn
Johnny Mo
DB617
Member
Posts: 1286
Joined: Mon Dec 25, 2017 00:51
Location: Bristol

Re: Should the NSL sign be abandoned?

Post by DB617 »

Something that's confusing me a little bit with this discussion is the idea that NSL roads are the only ones where drivers have to judge their speed, as on legacy roads, it is possible, nay likely, that design speed has not been ascertained or updated for modern standards. Surely this is not only true of NSL but of many 50 or 40 roads, too? Certainly driving in the Marches countryside in particular I have found that rural roads tend to have limits like 50 or 40 imposed where the horizontal or vertical geometry becomes more generally challenging, but sections will be capable of the speed limit while the bends are often advisory signed down to as low as 20mph. It seems that Herefordshire and Shropshire have done a lot of work assessing the safe speeds of their rural roads compared to, say, the various Glamorganshire or Somerset local authorities.

Are we on this forum prone to this misconception that NSL roads somehow confer more responsibility on drivers to judge speed? This is something that should be resisted as the number of roads speed limited for safety or environmental reasons rises precipitously.

On a separate note, I do think the NSL sign should be abandoned for new build roads. As we take a design speed approach to all new road schemes, such as the A4226 near where I grew up, it seems a little odd to design for a 100km/h speed and then sign as NSL rather than stating the (next lowest) design speed in mph. Drivers are already required to know their vehicle's permitted maxima for different road types e.g. 50mph for vans on single carriageways - it just seems a bit superfluous. It also produces a lot of confusion where NSL signs are posted both at the entrances to our tiniest, most horrible lanes and our newest, overbuilt DMRB roads.
SteelCamel
Member
Posts: 600
Joined: Fri Mar 27, 2020 15:46

Re: Should the NSL sign be abandoned?

Post by SteelCamel »

FosseWay wrote: Sat Jun 25, 2022 12:33 On the other hand, I think we should be a bit less hidebound about signage rules. For example, I see no reason not to use 30 repeaters on a default 30 stretch if there is a known problem with people driving faster than that.
I think the idea is to avoid "creep". If repeaters are installed on a few roads, there will be calls to install more. When a good chunk of roads have 30 repeaters, there may be a perception that roads without them aren't 30, so more roads get them installed until they're required everywhere.
If you really want 30 repeaters you can have them - install camera warning signs incorporating a 30 repeater. These are definitely allowed, and there's no requirement on how often the camera is there.
User avatar
KeithW
Member
Posts: 19201
Joined: Thu Dec 04, 2014 13:25
Location: Marton-In-Cleveland North Yorks

Re: Should the NSL sign be abandoned?

Post by KeithW »

DB617 wrote: Sat Jun 25, 2022 13:56 Something that's confusing me a little bit with this discussion is the idea that NSL roads are the only ones where drivers have to judge their speed, as on legacy roads, it is possible, nay likely, that design speed has not been ascertained or updated for modern standards. Surely this is not only true of NSL but of many 50 or 40 roads, too? Certainly driving in the Marches countryside in particular I have found that rural roads tend to have limits like 50 or 40 imposed where the horizontal or vertical geometry becomes more generally challenging, but sections will be capable of the speed limit while the bends are often advisory signed down to as low as 20mph. It seems that Herefordshire and Shropshire have done a lot of work assessing the safe speeds of their rural roads compared to, say, the various Glamorganshire or Somerset local authorities.

Are we on this forum prone to this misconception that NSL roads somehow confer more responsibility on drivers to judge speed? This is something that should be resisted as the number of roads speed limited for safety or environmental reasons rises precipitously.

On a separate note, I do think the NSL sign should be abandoned for new build roads. As we take a design speed approach to all new road schemes, such as the A4226 near where I grew up, it seems a little odd to design for a 100km/h speed and then sign as NSL rather than stating the (next lowest) design speed in mph. Drivers are already required to know their vehicle's permitted maxima for different road types e.g. 50mph for vans on single carriageways - it just seems a bit superfluous. It also produces a lot of confusion where NSL signs are posted both at the entrances to our tiniest, most horrible lanes and our newest, overbuilt DMRB roads.
There are some new roads that dont seem to have design speed limits but the reality is a sensible driver always drives to the conditions. It its foggy, icy, there is torrential rain, spray etc then you drive at the speed that is safe for those conditions and hang the design speed. This applies to all roads NSL or a lower signed limit. I have driven at under 30 in a 50 limit because I would not have seen a hazard in time to stop otherwise.
Post Reply