NSL Logic

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Vierwielen
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Re: NSL Logic

Post by Vierwielen »

trickstat wrote: Thu Jun 30, 2022 10:43
Vierwielen wrote: Thu Jun 30, 2022 08:31
ajuk wrote: Thu Jun 30, 2022 01:39 I don't know if it's a recent thing, but South Gloucestershire have been forced remove 30mph repeaters on roads with street lights. Are the DfT enforcing this rule now? It's a shame they can't also enforce speed limit setting guidelines. Although I've noticed Highways England have stared to disregard these now putting in an arbitrary "buffer zone" and ridding the preceding village of it's drop in speed limit in a place where it clearly makes sense.
But what happens if they turn those lights off at 02:00 to save energy? How are motorists expected to know that they are in a 30 mph zone?
If they can't see that there are streetlights present with their headlights on perhaps they shouldn't be driving at night?
The posts for the street lights might well be hidden by vegetation (as is the case of many road signs), especially if they are set a metre or two back from the kerb.
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Re: NSL Logic

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Vierwielen wrote: Thu Jun 30, 2022 22:41
trickstat wrote: Thu Jun 30, 2022 10:43
Vierwielen wrote: Thu Jun 30, 2022 08:31
But what happens if they turn those lights off at 02:00 to save energy? How are motorists expected to know that they are in a 30 mph zone?
If they can't see that there are streetlights present with their headlights on perhaps they shouldn't be driving at night?
The posts for the street lights might well be hidden by vegetation (as is the case of many road signs), especially if they are set a metre or two back from the kerb.
The lights could be mounted on buildings, as happens in the City and in York. The 30 limit would still apply, though, however improbable it might be that a motorist would see it at night and see enough to judge that the unlit lights were less than a certain distance apart. The law isn’t perfect in this regard but it has stood for 88 years now.
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Re: NSL Logic

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Vierwielen wrote: Thu Jun 30, 2022 22:41
trickstat wrote: Thu Jun 30, 2022 10:43
Vierwielen wrote: Thu Jun 30, 2022 08:31
But what happens if they turn those lights off at 02:00 to save energy? How are motorists expected to know that they are in a 30 mph zone?
If they can't see that there are streetlights present with their headlights on perhaps they shouldn't be driving at night?
The posts for the street lights might well be hidden by vegetation (as is the case of many road signs), especially if they are set a metre or two back from the kerb.
If the posts are hidden by vegetation there’s a fair chance repeaters mounted onto lampposts would be hidden too.
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Re: NSL Logic

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Then again, what are the chances that there will be a police van checking speeds in the early hours? Practically zero I'd say. A very large proportion, perhaps the majority, of roads that are subject to 30 limits are clearly residential or lined with shops.
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Re: NSL Logic

Post by KeithW »

Vierwielen wrote: Thu Jun 30, 2022 22:41 The posts for the street lights might well be hidden by vegetation (as is the case of many road signs), especially if they are set a metre or two back from the kerb.
One or two might be but the reality is most will not. In suburban and urban areas they are typically 15 to 20 ft tall, painted light grey and have various signs fastened to them.

Here is about as leafy a suburb as I know of and while some posts are partly hidden by vegetation you would hard pressed NOT to know the road had a street light system.

https://www.google.co.uk/maps/@54.52262 ... 8192?hl=en

Be thankful the roads dint have explicit signs as they as usually 20 mph limits.
https://www.google.co.uk/maps/@54.52235 ... 8192?hl=en
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Re: NSL Logic

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trickstat wrote: Thu Jun 30, 2022 23:22 Then again, what are the chances that there will be a police van checking speeds in the early hours? Practically zero I'd say. A very large proportion, perhaps the majority, of roads that are subject to 30 limits are clearly residential or lined with shops.
Well there are these things called speed cameras which never take a nap and Cleveland Police will often have talivans in random locations. This is one road where they will be catching a lot of people over the next month as the limits has been reduced to 30 due to the number of new housing developments.
https://www.google.co.uk/maps/@54.51913 ... 8192?hl=en
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Re: NSL Logic

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KeithW wrote: Fri Jul 01, 2022 12:06
trickstat wrote: Thu Jun 30, 2022 23:22 Then again, what are the chances that there will be a police van checking speeds in the early hours? Practically zero I'd say. A very large proportion, perhaps the majority, of roads that are subject to 30 limits are clearly residential or lined with shops.
Well there are these things called speed cameras which never take a nap and Cleveland Police will often have talivans in random locations. This is one road where they will be catching a lot of people over the next month as the limits has been reduced to 30 due to the number of new housing developments.
https://www.google.co.uk/maps/@54.51913 ... 8192?hl=en
One thing very apparent from comments on here is that the prevalence of speed cameras and talivans does vary quite a lot between local authority areas. Here in Letchworth, the only cameras I'm aware of are on the A505 and I don't think I have ever seen a talivan anywhere in the town. The latter are not uncommon on the 40mph dual carriageways in Stevenage, however.
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Re: NSL Logic

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Chris5156 wrote: Thu Jun 30, 2022 22:46
Vierwielen wrote: Thu Jun 30, 2022 22:41
trickstat wrote: Thu Jun 30, 2022 10:43

If they can't see that there are streetlights present with their headlights on perhaps they shouldn't be driving at night?
The posts for the street lights might well be hidden by vegetation (as is the case of many road signs), especially if they are set a metre or two back from the kerb.
The lights could be mounted on buildings, as happens in the City and in York. The 30 limit would still apply, though, however improbable it might be that a motorist would see it at night and see enough to judge that the unlit lights were less than a certain distance apart. The law isn’t perfect in this regard but it has stood for 88 years now.
What was the law during the war years when all the street lights were turned off? The obvious answer of course is that due to petrol rationing, hardly anybody drove unless they had to.
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Re: NSL Logic

Post by Ruperts Trooper »

Vierwielen wrote: Fri Jul 01, 2022 17:46
Chris5156 wrote: Thu Jun 30, 2022 22:46
Vierwielen wrote: Thu Jun 30, 2022 22:41
The posts for the street lights might well be hidden by vegetation (as is the case of many road signs), especially if they are set a metre or two back from the kerb.
The lights could be mounted on buildings, as happens in the City and in York. The 30 limit would still apply, though, however improbable it might be that a motorist would see it at night and see enough to judge that the unlit lights were less than a certain distance apart. The law isn’t perfect in this regard but it has stood for 88 years now.
What was the law during the war years when all the street lights were turned off? The obvious answer of course is that due to petrol rationing, hardly anybody drove unless they had to.
And the KSI rate ballooned during the blackout - although how much was due to lack of streetlights and how much due to restricting vehicles' already poor output to a simple slit isn't known.
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Re: NSL Logic

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Vierwielen wrote: Fri Jul 01, 2022 17:46
Chris5156 wrote: Thu Jun 30, 2022 22:46
Vierwielen wrote: Thu Jun 30, 2022 22:41
The posts for the street lights might well be hidden by vegetation (as is the case of many road signs), especially if they are set a metre or two back from the kerb.
The lights could be mounted on buildings, as happens in the City and in York. The 30 limit would still apply, though, however improbable it might be that a motorist would see it at night and see enough to judge that the unlit lights were less than a certain distance apart. The law isn’t perfect in this regard but it has stood for 88 years now.
What was the law during the war years when all the street lights were turned off? The obvious answer of course is that due to petrol rationing, hardly anybody drove unless they had to.
The same. Whether they were on or off, the streetlights were present, and that is all that matters.
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Re: NSL Logic

Post by Bryn666 »

Chris5156 wrote: Fri Jul 01, 2022 19:12
Vierwielen wrote: Fri Jul 01, 2022 17:46
Chris5156 wrote: Thu Jun 30, 2022 22:46
The lights could be mounted on buildings, as happens in the City and in York. The 30 limit would still apply, though, however improbable it might be that a motorist would see it at night and see enough to judge that the unlit lights were less than a certain distance apart. The law isn’t perfect in this regard but it has stood for 88 years now.
What was the law during the war years when all the street lights were turned off? The obvious answer of course is that due to petrol rationing, hardly anybody drove unless they had to.
The same. Whether they were on or off, the streetlights were present, and that is all that matters.
Interestingly though over in the USA where fuel was not rationed into near non-existence (there was very little private motoring here because of the need to maintain war supply) they had the Victory Speed of 35 mph everywhere which predated the second patriotic fuel saving 55 limit 30 years later...

Whilst the USA was busy building freeways in the late 1940s we didn't take petrol off ration until 1950.
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Re: NSL Logic

Post by KeithW »

Vierwielen wrote: Fri Jul 01, 2022 17:46
What was the law during the war years when all the street lights were turned off? The obvious answer of course is that due to petrol rationing, hardly anybody drove unless they had to.
There was a lot of traffic on the roads but very few private motorists. In 1939 there were 2 million cars on the road, that of course declined enormously but the expansion of the army and air force more than covered that. In 1939 the army had 40,000 vehicles, by 1944 it had 1.5 million. Road Freight

During WW2 Ford Dagenham produced 360,000 vehicles and they opened a second factory in Manchester

The Rootes group made the Humber staff car, scout cars and armoured cars, the Humber 8cwt 4x4 field ambulance, the Hillman 10HP Tilly and the Karrier four-wheel-drive three-ton truck.

Scammel switched to making recovery trucks and Tank transporters

Vauxhall largely switched to making Bedford trucks

Morris made 4x4 gun carriage and 10HP Tilly, scout cars, amphibious DUKWs, plus the Morris Commercial C8 FAT (Field Artillery Tractor), commonly known as the Quad.

Then there the large numbers of US military vehicles that started arriving en mass in 1943 which I suspect did little for road safety. The statistics show a sharp rise in fatalities peaking in 1941 and a sharp drop between 1945 and 1950.
Road freight showed a small decline between 1939 and 1941 but had recovered by 1945.
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Re: NSL Logic

Post by Vierwielen »

Ruperts Trooper wrote: Fri Jul 01, 2022 19:02
Vierwielen wrote: Fri Jul 01, 2022 17:46
Chris5156 wrote: Thu Jun 30, 2022 22:46
The lights could be mounted on buildings, as happens in the City and in York. The 30 limit would still apply, though, however improbable it might be that a motorist would see it at night and see enough to judge that the unlit lights were less than a certain distance apart. The law isn’t perfect in this regard but it has stood for 88 years now.
What was the law during the war years when all the street lights were turned off? The obvious answer of course is that due to petrol rationing, hardly anybody drove unless they had to.
And the KSI rate ballooned during the blackout - although how much was due to lack of streetlights and how much due to restricting vehicles' already poor output to a simple slit isn't known.
Given that vehicles were restricted to a narrow beam of light via a slit and that there were no street lights, it is highly probably that exceeding the 30 mph speed limit at night time was not a very clever thing to do.
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Re: NSL Logic

Post by ajuk »

Vierwielen wrote: Thu Jun 30, 2022 08:31
ajuk wrote: Thu Jun 30, 2022 01:39 I don't know if it's a recent thing, but South Gloucestershire have been forced remove 30mph repeaters on roads with street lights. Are the DfT enforcing this rule now? It's a shame they can't also enforce speed limit setting guidelines. Although I've noticed Highways England have stared to disregard these now putting in an arbitrary "buffer zone" and ridding the preceding village of it's drop in speed limit in a place where it clearly makes sense.
But what happens if they turn those lights off at 02:00 to save energy? How are motorists expected to know that they are in a 30 mph zone?
The lights are still there just turned off.
That said, they turn off the lights in the town I live I do support them doing that, however I think the ones they should leave one are the lights by the most important junctions, the odd light on main road roads and the first light for each entrance to the town.
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Re: NSL Logic

Post by Vierwielen »

ajuk wrote: Sat Jul 02, 2022 01:43
Vierwielen wrote: Thu Jun 30, 2022 08:31
ajuk wrote: Thu Jun 30, 2022 01:39 I don't know if it's a recent thing, but South Gloucestershire have been forced remove 30mph repeaters on roads with street lights. Are the DfT enforcing this rule now? It's a shame they can't also enforce speed limit setting guidelines. Although I've noticed Highways England have stared to disregard these now putting in an arbitrary "buffer zone" and ridding the preceding village of it's drop in speed limit in a place where it clearly makes sense.
But what happens if they turn those lights off at 02:00 to save energy? How are motorists expected to know that they are in a 30 mph zone?
The lights are still there just turned off.
That said, they turn off the lights in the town I live I do support them doing that, however I think the ones they should leave one are the lights by the most important junctions, the odd light on main road roads and the first light for each entrance to the town.
It is quite possible that the "odd light on main roads" are spaced a little uner 185 metres apart so as to keep the 30 mph limit in place, otherwise Mr Loophole migth get a new case to work on.
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Re: NSL Logic

Post by PhilC »

Vierwielen wrote: Fri Jul 01, 2022 17:46 What was the law during the war years when all the street lights were turned off? The obvious answer of course is that due to petrol rationing, hardly anybody drove unless they had to.
During blackout hours in the second world war there was a temporary 20mph speed limit. I don't think it did much to reduce accidents though.
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Re: NSL Logic

Post by Fenlander »

Vierwielen wrote: Sat Jul 02, 2022 21:45 It is quite possible that the "odd light on main roads" are spaced a little uner 185 metres apart so as to keep the 30 mph limit in place, otherwise Mr Loophole migth get a new case to work on.
183 not 185 (the metric equivalent of the stated 200yards).
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Re: NSL Logic

Post by Chris Bertram »

Fenlander wrote: Wed Jul 06, 2022 13:27
Vierwielen wrote: Sat Jul 02, 2022 21:45 It is quite possible that the "odd light on main roads" are spaced a little uner 185 metres apart so as to keep the 30 mph limit in place, otherwise Mr Loophole migth get a new case to work on.
183 not 185 (the metric equivalent of the stated 200yards).
Isn't it 185 in Scotland?
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Re: NSL Logic

Post by KrisW »

This rule always seemed to me to be needlessy obtuse, and to work against the basic idea of setting speed limits in the first place, which is to get people to drive slower. If you want people to slow down, tell them to do so - don’t make them guess how far apart lamp-posts are.

A couple of simple changes would help a lot: first, change the design manual to advise that repeater signs should be used where the driver may be in doubt that they’re in a built-up area; and second, a change in the law to finally break the arbitrary link between speed and street lighting. The fact that, even on this site, people are discussing the exact rules means that it has completely failed as a means of communicating a speed limit. My guess is that most cases where this law would apply are already signed with repeaters anyway, precisely because the law is so poorly understood (and a sizeable minority of drivers did not learn to drive in the UK).

If I was going further, a better, but more expensive, approach would be to abolish the NSL sign entirely, and explicitly sign all speed-limits. This is what Ireland did when we moved to metric speed limits. Part of the reason for the abolition was that the complicated rules from the UK about what the sign meant had spread confusion in Ireland about its meaning (it always meant “60 mph limit” over here, regardless of siting), and that those differences in meaning encouraged visitors from the UK to exceed the speed-limit on dual carriageways.

To accompany the abolition of the NSL sign, limit repeater signs were installed, even on open-road stretches, and all non-national routes (i.e., “B-Roads” and below) were reduced to 80km/h unless signed otherwise. That latter rule was communicated as “if the signs are white, the limit is 80km/h unless you see a higher limit posted”, but repeaters were installed too as reminders. The de facto outcome of these changes was to set the “default” speed limit to 80km/h with higher limits of 100 and 120 km/h permitted on specific roads.
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Re: NSL Logic

Post by Bryn666 »

But Ireland has had to reintroduce a variant of the NSL sign because explicit 80 signs on borreens was rightly seen as a national joke.

The easiest and cheapest way to make sure people know their speed limits is a public awareness campaign followed by heavy police enforcement. Abolishing the NSL sign won't stop speeding as the bulk of speeding vehicles are in 30 limits and on motorways, neither of which require an NSL sign.
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