Dual carriageway hatched centre
Discussion
While we're discussing hatchings
I drove along a pice of dual carriageway yesterday that instead of a kerbed central reservation had double dashed lines with hashing between them to divide the two sets of 2 lanes
On one of the lamposts was the usual blue informative NSL and camera sign.
What's the speed limit?
Is it really a dual carriageway or is it counted as a 4 lane road with hatching so 60 rather than 70.
I drove along a pice of dual carriageway yesterday that instead of a kerbed central reservation had double dashed lines with hashing between them to divide the two sets of 2 lanes
On one of the lamposts was the usual blue informative NSL and camera sign.
What's the speed limit?
Is it really a dual carriageway or is it counted as a 4 lane road with hatching so 60 rather than 70.
Road Traffic Regulation Act 1984
“dual-carriageway road” means a road part of which consists of a central reservation to separate a carriageway to be used by vehicles proceeding in one direction from a carriageway to be used by vehicles proceeding in the opposite direction;
In this case there is no central reservation seperating the carriageways just lines so DC status for 70 mph does not exists so its NSL i.e. a fourlane carriageway.
dvd
“dual-carriageway road” means a road part of which consists of a central reservation to separate a carriageway to be used by vehicles proceeding in one direction from a carriageway to be used by vehicles proceeding in the opposite direction;
In this case there is no central reservation seperating the carriageways just lines so DC status for 70 mph does not exists so its NSL i.e. a fourlane carriageway.
dvd
tvrgit said:
saaby93 said:
blue infotmatory NSL sign
what's that? NSL signs are White / black
It had one of those on an oblong blue background with the camera sign above it
blue = information
It's there in case you're unsure what the limit is.
If the lines either side of the hatching had been solid as in gaps in normal dual carriageways (or are those dashed too) would it then be 70?
At what distance does it change from being a gap in a dual carriageway to being 4 lane road in its own right.
It was roundabout separated from 'proper' dual cariageways
saaby93 said:
tvrgit said:
saaby93 said:
blue infotmatory NSL sign
what's that? NSL signs are White / blackIt had one of those on an oblong blue background with the camera sign above it
blue = information
It's there in case you're unsure what the limit is.
If the lines either side of the hatching had been solid as in gaps in normal dual carriageways (or are those dashed too) would it then be 70?
At what distance does it change from being a gap in a dual carriageway to being 4 lane road in its own right.
It was roundabout separated from 'proper' dual cariageways
esselte said:
saaby93 said:
tvrgit said:
saaby93 said:
blue infotmatory NSL sign
what's that? NSL signs are White / blackIt had one of those on an oblong blue background with the camera sign above it
blue = information
It's there in case you're unsure what the limit is.
If the lines either side of the hatching had been solid as in gaps in normal dual carriageways (or are those dashed too) would it then be 70?
At what distance does it change from being a gap in a dual carriageway to being 4 lane road in its own right.
It was roundabout separated from 'proper' dual cariageways
...as long as the central 'reservation' is more substantial than painted line(s) a dual carriageway it isoldsoak said:
...as long as the central 'reservation' is more substantial than painted line(s) a dual carriageway it isWhat theyd done was obviously more substantial than the usual longer dashes on a 4 lane road - and the hatching was 2-3ft wide
Thoughts were :-
a) Why couldnt they be bothered to put an inch of tarmac along there
b) I'n none the wiser with that 'informative' sign
saaby93 said:
oldsoak said:
...as long as the central 'reservation' is more substantial than painted line(s) a dual carriageway it isWhat theyd done was obviously more substantial than the usual longer dashes on a 4 lane road - and the hatching was 2-3ft wide
Thoughts were :-
a) Why couldnt they be bothered to put an inch of tarmac along there
b) I'n none the wiser with that 'informative' sign
definition of a central reservation is "permanent construction or other land"
So other land would be for example a central grass strip bounded by kerbs or not. A permanent construction could consist of kerbs surrounding a paved or concreted area, with or without a central barrier. Permanent constructions see?
White paint or any other colour of paint applied to a strip of tarmac cannot make a central reserve as it is not classed as a permanent construction. End of. Full stop. Rule off.
The question you ask about gaps in a central reserve is a valid one, such gaps are usually present at junctions and crossovers. How big does a gap have to be to cause a dual carriageway to cease to be a DC? The corollary of this being how big does a traffic island have to be to acquire status as a central reserve? To my knowledge these matters are not defined in law.
So other land would be for example a central grass strip bounded by kerbs or not. A permanent construction could consist of kerbs surrounding a paved or concreted area, with or without a central barrier. Permanent constructions see?
White paint or any other colour of paint applied to a strip of tarmac cannot make a central reserve as it is not classed as a permanent construction. End of. Full stop. Rule off.
The question you ask about gaps in a central reserve is a valid one, such gaps are usually present at junctions and crossovers. How big does a gap have to be to cause a dual carriageway to cease to be a DC? The corollary of this being how big does a traffic island have to be to acquire status as a central reserve? To my knowledge these matters are not defined in law.
saaby93 said:
oldsoak said:
...as long as the central 'reservation' is more substantial than painted line(s) a dual carriageway it isWhat theyd done was obviously more substantial than the usual longer dashes on a 4 lane road - and the hatching was 2-3ft wide
Thoughts were :-
a) Why couldnt they be bothered to put an inch of tarmac along there
b) I'n none the wiser with that 'informative' sign
Yeah what FiF said ^^^
Edited by oldsoak on Saturday 3rd October 15:20
just to spam the thread.
The blue sign was an information sign that speed enforcement by cameras may be done along the road, and reminding drivers that the NSL was in force.
You don't mention whether the road had a system of street lighting in place and if so in this case it could be argued that the signs were also being used as limit repeaters.
The blue sign was an information sign that speed enforcement by cameras may be done along the road, and reminding drivers that the NSL was in force.
You don't mention whether the road had a system of street lighting in place and if so in this case it could be argued that the signs were also being used as limit repeaters.
There was a system of street lighting but there were no ordinary NSL repeater signs - wouldn't they need more than the blue informatory sign to cancel the street lights?
The SCP van was lurking..... but no worries
Isn't a strip of tarmac down the centre covered by white hashing more permanent than a strip of grass?
The SCP van was lurking..... but no worries
Isn't a strip of tarmac down the centre covered by white hashing more permanent than a strip of grass?
saaby93 said:
There was a system of street lighting but there were no ordinary NSL repeater signs - wouldn't they need more than the blue informatory sign to cancel the street lights?
The SCP van was lurking..... but no worries
Isn't a strip of tarmac down the centre covered by white hashing more permanent than a strip of grass?
There's usually a raised kerb when there's a grass reservation..The SCP van was lurking..... but no worries
Isn't a strip of tarmac down the centre covered by white hashing more permanent than a strip of grass?
saaby93 said:
Actually I think youve all just made me realise what its all about
As you say stretch of lookey likey dual carriageway between two stretches of real dual carriageway
Informative NSL sign which doesnt really tell you that the speed limit has changed
SCP van
Kerrrrrrrrching lol, don't you just love em ?As you say stretch of lookey likey dual carriageway between two stretches of real dual carriageway
Informative NSL sign which doesnt really tell you that the speed limit has changed
SCP van
F i F said:
The corollary of this being how big does a traffic island have to be to acquire status as a central reserve? To my knowledge these matters are not defined in law.
The minumium width of a C/R would be governed by the highway design standards (Design Manual for Roads and Bridges TD19/06). As a dual carriageway would become a 70mph road, then you would want barrier installed to keep accident casualties down. It would be a no brainer from a cost benefit point of view. The current standards don't state a minimum width, but realistically when you've factored in minimum clearances from appurtenances its going to be at least 1.5m ish depending what type of fence/barrier you use.Installing hatched white lines in the centre pof a single carriageway would be a proportional safety measure to counter the problem. Next option would probably be reducing the speed limit, if the line painting does not deliver a required safety benefit after 2-3 yrs. The cost to install a proper centre reserve would require more land uptake to maintain the number of lanes and costs soon spiral.
Are those the requirements for new build?
I know of a number of dual carriageways without a central fence and less than 1.5 metres wide raised lump in the middle - probably 2ft.
Obviously there arent accidents or there would be the calls for something more substantial down the middle
Which as usual makes me question whther lack of a fence makes motorists drive more carefully as it looks more dangerous
I know of a number of dual carriageways without a central fence and less than 1.5 metres wide raised lump in the middle - probably 2ft.
Obviously there arent accidents or there would be the calls for something more substantial down the middle
Which as usual makes me question whther lack of a fence makes motorists drive more carefully as it looks more dangerous
Highway design standards have evolved over the years, so its possible they were built to older standards with different requirements.
Could you names some dual carriageways with 70mph limit and no central barrier and only 2ft hardstanding? I'm intrigued.
I know of the A1081 London Colney Bypass but there is a very wide grass verge well over 3m width in places with shrubs/bushes dotted along it.
The A406 North Circular at Henlys corner/A1 has a very narrow center reserve maybe less than 1m and includes street lights! but this is a 40mph road. However newer sections of the A406 east towards Beckton are 50mph with safety fence and the c/r is extremely narrow about as narrow as you could get away with.
Could you names some dual carriageways with 70mph limit and no central barrier and only 2ft hardstanding? I'm intrigued.
I know of the A1081 London Colney Bypass but there is a very wide grass verge well over 3m width in places with shrubs/bushes dotted along it.
The A406 North Circular at Henlys corner/A1 has a very narrow center reserve maybe less than 1m and includes street lights! but this is a 40mph road. However newer sections of the A406 east towards Beckton are 50mph with safety fence and the c/r is extremely narrow about as narrow as you could get away with.
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