NSL to a 20 limit?

[tonyvid]

I was up in Norfolk the other day and came across a single carriageway NSL straight into a 20 limit...I was under the impression they had to go down via another step, is that the case?

[Flat in Fifth]

Nope, I had almost the same experience on an off slip from the M6 near Brum.

70>20 in one hit. OK to be fair only a total twonk would have been doing 70, or in fact anything above 45-ish, but even so to round a bend and be confronted with a 20 sign 50 yds after the bend was a shade off putting to say the least.

Plus the extremely vulnerable feeling of then sitting there at 20 and watching the mirrors nervously.

[tigger1]

Flat in Fifth said:

Plus the extremely vulnerable feeling of then sitting there at 20 and watching the mirrors nervously.

And even worse - if people slow in front of you, before the sign (as legally required) you have people doing FIFTY mph under the posted limit...something that would be considered DwDCaA on a motorway by many.

[Andrew D]

There isn't a hard and fast rule that requires a gradual change in limit, but it's (becoming) good*/common practice to introduce steps on trunk roads. Obviously big jumps are faily common in rural settings and at urban motorway junctions, but rural NSL (i.e. single carriageway) to 20mph is a new one on me!

* In my opinion it's only necessary if you assume drivers are driving to the limit rather than the road geometry, as they'd be able to see the change coming in time in the latter case.

[philbes]

Andrew D said:

* In my opinion it's only necessary if you assume drivers are driving to the limit rather than the road geometry, as they'd be able to see the change coming in time in the latter case.

That would be true if speed limits were matched to road geometry but we all know of many places where that is no longer the case.

[Andrew D]

philbes said:

Andrew D said:

* In my opinion it's only necessary if you assume drivers are driving to the limit rather than the road geometry, as they'd be able to see the change coming in time in the latter case.

That would be true if speed limits were matched to road geometry but we all know of many places where that is no longer the case.

My point is that if you're driving at a speed at which you can stop, or at least slow appreciably, in the distance you can see, then there's no need for a gradual reduction in limit as you'll be able to see the 20mph sign and slow from whatever speed you're doing in time.

[a boardman]

Hi I am new here.

Just out of interest in this point, under the Road signs manual chapter 5 (I think that is right) this covers road markings.

The regulations for centre lines are different for speed limits over 40mph and under 40mph.

so if the council has not changed the centre road markings to suit the now lower limit is the speed limit still valid, after all yellow lines are only valid if they are done as per the manual ie crossed ends etc...

[Flat in Fifth]

Andrew D said:

philbes said:

Andrew D said:

* In my opinion it's only necessary if you assume drivers are driving to the limit rather than the road geometry, as they'd be able to see the change coming in time in the latter case.

That would be true if speed limits were matched to road geometry but we all know of many places where that is no longer the case.

My point is that if you're driving at a speed at which you can stop, or at least slow appreciably, in the distance you can see, then there's no need for a gradual reduction in limit as you'll be able to see the 20mph sign and slow from whatever speed you're doing in time.

That's all very well and true, however the circumstances I described were such that the 20 signs, which were actually for suspended roadworks, were positioned just round a bend and were unsighted. Now as said earlier, although the limit was technically 70 and motorway rules still applied only an utter idiot would have been going at 70, 50 would have been pushing it and an appropriate speed was, in my opinion, around 40-45.

Nevertheless the positioning of the 20 signs meant that it was absolutely impossible to reduce speed using acceleration sense, and whilst it was possible to reduce speed to 20 by the limit sign, in order to do it smoothly, ie tapered at commencement and end of braking, some fairly firm retardation was needed.

Now couple that with doing 20 in a position where someone, in theory, could come round the bend say 50 yds behind you but doing 70, well it doesn't sit well with me anyway.

[herewego]

Flat in Fifth said:

Andrew D said:

philbes said:

Andrew D said:

* In my opinion it's only necessary if you assume drivers are driving to the limit rather than the road geometry, as they'd be able to see the change coming in time in the latter case.

That would be true if speed limits were matched to road geometry but we all know of many places where that is no longer the case.

My point is that if you're driving at a speed at which you can stop, or at least slow appreciably, in the distance you can see, then there's no need for a gradual reduction in limit as you'll be able to see the 20mph sign and slow from whatever speed you're doing in time.

That's all very well and true, however the circumstances I described were such that the 20 signs, which were actually for suspended roadworks, were positioned just round a bend and were unsighted. Now as said earlier, although the limit was technically 70 and motorway rules still applied only an utter idiot would have been going at 70, 50 would have been pushing it and an appropriate speed was, in my opinion, around 40-45.

Nevertheless the positioning of the 20 signs meant that it was absolutely impossible to reduce speed using acceleration sense, and whilst it was possible to reduce speed to 20 by the limit sign, in order to do it smoothly, ie tapered at commencement and end of braking, some fairly firm retardation was needed.

Now couple that with doing 20 in a position where someone, in theory, could come round the bend say 50 yds behind you but doing 70, well it doesn't sit well with me anyway.

Aren't you supposed to be able to stop within the distance you can see or something?

[Stu R]

Are 20mph speed limits enforcable? I always thought 30 was the lowest limit you'd get points and a fine for, but I'm under the impression that's not the case? Just out of curiosity more than anything, apologies if it's a daft question

[Flat in Fifth]

herewego said:

Flat in Fifth said:

Andrew D said:

philbes said:

Andrew D said:

* In my opinion it's only necessary if you assume drivers are driving to the limit rather than the road geometry, as they'd be able to see the change coming in time in the latter case.

That would be true if speed limits were matched to road geometry but we all know of many places where that is no longer the case.

My point is that if you're driving at a speed at which you can stop, or at least slow appreciably, in the distance you can see, then there's no need for a gradual reduction in limit as you'll be able to see the 20mph sign and slow from whatever speed you're doing in time.

That's all very well and true, however the circumstances I described were such that the 20 signs, which were actually for suspended roadworks, were positioned just round a bend and were unsighted. Now as said earlier, although the limit was technically 70 and motorway rules still applied only an utter idiot would have been going at 70, 50 would have been pushing it and an appropriate speed was, in my opinion, around 40-45.

Nevertheless the positioning of the 20 signs meant that it was absolutely impossible to reduce speed using acceleration sense, and whilst it was possible to reduce speed to 20 by the limit sign, in order to do it smoothly, ie tapered at commencement and end of braking, some fairly firm retardation was needed.

Now couple that with doing 20 in a position where someone, in theory, could come round the bend say 50 yds behind you but doing 70, well it doesn't sit well with me anyway.

Aren't you supposed to be able to stop within the distance you can see or something?

where did I say that I could not have stopped?

[herewego]

Flat in Fifth said:

herewego said:

Flat in Fifth said:

Andrew D said:

philbes said:

Andrew D said:

* In my opinion it's only necessary if you assume drivers are driving to the limit rather than the road geometry, as they'd be able to see the change coming in time in the latter case.

That would be true if speed limits were matched to road geometry but we all know of many places where that is no longer the case.

My point is that if you're driving at a speed at which you can stop, or at least slow appreciably, in the distance you can see, then there's no need for a gradual reduction in limit as you'll be able to see the 20mph sign and slow from whatever speed you're doing in time.

That's all very well and true, however the circumstances I described were such that the 20 signs, which were actually for suspended roadworks, were positioned just round a bend and were unsighted. Now as said earlier, although the limit was technically 70 and motorway rules still applied only an utter idiot would have been going at 70, 50 would have been pushing it and an appropriate speed was, in my opinion, around 40-45.

Nevertheless the positioning of the 20 signs meant that it was absolutely impossible to reduce speed using acceleration sense, and whilst it was possible to reduce speed to 20 by the limit sign, in order to do it smoothly, ie tapered at commencement and end of braking, some fairly firm retardation was needed.

Now couple that with doing 20 in a position where someone, in theory, could come round the bend say 50 yds behind you but doing 70, well it doesn't sit well with me anyway.

Aren't you supposed to be able to stop within the distance you can see or something?

where did I say that I could not have stopped?

I was talking about the theoretical person behind you.

[Flat in Fifth]

herewego said:

Flat in Fifth said:

herewego said:

Flat in Fifth said:

Andrew D said:

philbes said:

Andrew D said:

* In my opinion it's only necessary if you assume drivers are driving to the limit rather than the road geometry, as they'd be able to see the change coming in time in the latter case.

That would be true if speed limits were matched to road geometry but we all know of many places where that is no longer the case.

My point is that if you're driving at a speed at which you can stop, or at least slow appreciably, in the distance you can see, then there's no need for a gradual reduction in limit as you'll be able to see the 20mph sign and slow from whatever speed you're doing in time.

That's all very well and true, however the circumstances I described were such that the 20 signs, which were actually for suspended roadworks, were positioned just round a bend and were unsighted. Now as said earlier, although the limit was technically 70 and motorway rules still applied only an utter idiot would have been going at 70, 50 would have been pushing it and an appropriate speed was, in my opinion, around 40-45.

Nevertheless the positioning of the 20 signs meant that it was absolutely impossible to reduce speed using acceleration sense, and whilst it was possible to reduce speed to 20 by the limit sign, in order to do it smoothly, ie tapered at commencement and end of braking, some fairly firm retardation was needed.

Now couple that with doing 20 in a position where someone, in theory, could come round the bend say 50 yds behind you but doing 70, well it doesn't sit well with me anyway.

Aren't you supposed to be able to stop within the distance you can see or something?

where did I say that I could not have stopped?

I was talking about the theoretical person behind you.

Ah OK sorry, seeing as it's you I'll let you off.

Yes you are right though, one is supposed to be able to do so, but how many people actually do that? How many drive on what they expect the situation will be rather than the what if scenario? As in "but I turn right here every day and there's never anything coming!"

[tvrgit]

Stu R said:

Are 20mph speed limits enforcable? I always thought 30 was the lowest limit you'd get points and a fine for, but I'm under the impression that's not the case? Just out of curiosity more than anything, apologies if it's a daft question

some 20 mph signs. for example home zones, are indeed advisory, because they are not backed up by a traffic regulation order to give effect to a lower ebforceable limit.

Some limits are enforceable though, if the highway authority has made the necessary order.

Usual rule - if the 20 sign has a red border, it's enforceable, if it's green or black, it's not.

In answer to another question: the white line modules in the TSM are indeed different for limits above and below 40 - but if they are not consistent, it's the white line that's wrong, not the limit - the traffic regulation order takes precedence and the it's the speed limit signs that give effect to that order, not the white lines. The wrong white lines do not make the limit unenforceable - they are not a speed limit sign in themselves (unlike yellow lines which are part of the signing of the order)

[Parrot of Doom]

Thats nothing. Try going west down the M56 out of Manchester, and leaving to go down the A556 towards the M6. Leaving via the sliproad off the M56, which has a 40mph limit sign at the very start of the slip road.

How on earth you're supposed to obey that one safely is beyond me.

[Vaux]

Parrot of Doom said:

Thats nothing. Try going west down the M56 out of Manchester, and leaving to go down the A556 towards the M6. Leaving via the sliproad off the M56, which has a 40mph limit sign at the very start of the slip road.

How on earth you're supposed to obey that one safely is beyond me.

When's the last time you drove it? The 40's been gone for a while now.

[Blue160]

On the subject of 20 limits not being enforceable.........

I know two people who have been done for 29mph over Tower Bridge

(For those that don't know this has a 20 limit enforced by SPECS)

[Blue160]

On the subject of 20 limits not being enforceable.........

I know two people who have been done for 29mph over Tower Bridge

(For those that don't know this has a 20 limit enforced by SPECS)