Why does the UK not have any D2+1 roads?

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
KeithW
Member
Posts: 19205
Joined: Thu Dec 04, 2014 13:25
Location: Marton-In-Cleveland North Yorks

Re: Why does the UK not have any D2+1 roads?

Post by KeithW »

nowster wrote: Fri Jan 07, 2022 18:59 But the danger markings don't switch over when the centre markings change...
Kindly define what you mean by danger markings
User avatar
IAN
Member
Posts: 1494
Joined: Thu Dec 20, 2001 19:07

Re: Why does the UK not have any D2+1 roads?

Post by IAN »

Not the original plan but we've ended up with this section of the A449 north of Worcester being converted to D2 +1

https://www.google.com/maps/@52.2501798 ... 384!8i8192
AKA M5 Driver
User avatar
Big L
Deputy Site Manager
Posts: 7517
Joined: Sun Nov 14, 2010 20:36
Location: B5012

Re: Why does the UK not have any D2+1 roads?

Post by Big L »

KeithW wrote: Fri Jan 07, 2022 19:57
nowster wrote: Fri Jan 07, 2022 18:59 But the danger markings don't switch over when the centre markings change...
Kindly define what you mean by danger markings
Longer 'centre' lines.
Make poetry history.

Did you know there's more to SABRE than just the Forums?
Help with maps using the new online calibrator.
Add your roads knowledge to the SABRE Wiki.
Peter Freeman
Member
Posts: 1390
Joined: Thu Aug 30, 2012 07:52
Location: Exits 9 & 10, M1 East, Melbourne, Australia

Re: Why does the UK not have any D2+1 roads?

Post by Peter Freeman »

A320Driver wrote: Thu Jan 06, 2022 15:24 Going by the nomenclature in another recent thread, shouldn’t it be D1+1? I.e. dual, one-lane carriageways, one of which has an extra lane?
Yes of course, it should be referred to as 'D1+1', if continuing Sabre's usual nomenclature. Compare 'S2+1'. 'D2+1' gives the incorrect impression that it's D2 with an added lane.

When referring to motorways with 3 lanes in one direction and 4 lanes in the other direction, I usually write D3/4. So the format under discussion here could be 'D1/2'.

An alternative would be 'S2+1 with central barrier' or 'S2+1 with safety barrier', since it's an S2+1 with an added feature (the barrier). The fact that the barrier is narrow, and usually made of wire rather than concrete (New Jersey), favours an S-name rather than a D-name - especially since most instances are upgrades to existing single carriageways, or short lengths on an otherwise-standard S2 or S2+1.
Last edited by Peter Freeman on Sat Jan 08, 2022 06:33, edited 1 time in total.
jabbaboy
Member
Posts: 358
Joined: Sun Jul 16, 2006 09:25
Location: Newcastle

Re: Why does the UK not have any D2+1 roads?

Post by jabbaboy »

Surprised no-one mentioned them but they're extremely cycle unfriendly so unless your offering an alternative then they'd never work. I know there's a few bus lanes locally up here that had dividers put in which were removed straight away for the same reason.

Then when your doing all that you've got the space for a dual carriageway anyway.
User avatar
KeithW
Member
Posts: 19205
Joined: Thu Dec 04, 2014 13:25
Location: Marton-In-Cleveland North Yorks

Re: Why does the UK not have any D2+1 roads?

Post by KeithW »

Big L wrote: Fri Jan 07, 2022 20:42
KeithW wrote: Fri Jan 07, 2022 19:57
nowster wrote: Fri Jan 07, 2022 18:59 But the danger markings don't switch over when the centre markings change...
Kindly define what you mean by danger markings
Longer 'centre' lines.
That is what I thought and the hazard in this case would be the fact that traffic in that lane is approaching the end of the relatively short S4 section.
https://www.google.com/maps/@54.8218359 ... a=!3m1!1e3
User avatar
JammyDodge
Member
Posts: 484
Joined: Sat Oct 13, 2018 13:17

Re: Why does the UK not have any D2+1 roads?

Post by JammyDodge »

jnty wrote: Thu Jan 06, 2022 14:45 I don't know of any NSL rural S4s but I'd imagine they're on roads so quiet that safety's not a huge consideration.
There is a small stretch of NSL S4 on the A6, south of Carlisle. Although, as you say, quite enough for it to have no issues
Designing Tomorrow, Around the Past
User avatar
Big Nick
Member
Posts: 4355
Joined: Tue Apr 24, 2007 08:27
Location: Epping, Essex

Re: Why does the UK not have any D2+1 roads?

Post by Big Nick »

KeithW wrote: Thu Jan 06, 2022 18:22
skiddaw05 wrote: Thu Jan 06, 2022 13:11 I've sometimes wondered this about that even rarer beast, the rural S4
I know of some in the North East - here is one to start with
https://www.google.co.uk/maps/@54.58910 ... 8192?hl=en
I thought you were going to mention Marton Road, or is it S2+2 because of the white paint down the centre?
https://goo.gl/maps/wtD9WHL3vPFrn47B8
WHBM
Member
Posts: 9707
Joined: Thu Nov 30, 2006 18:01
Location: London

Re: Why does the UK not have any D2+1 roads?

Post by WHBM »

User avatar
Bryn666
Elected Committee Member
Posts: 35755
Joined: Thu Jun 20, 2002 20:54
Contact:

Re: Why does the UK not have any D2+1 roads?

Post by Bryn666 »

Big Nick wrote: Sat Jan 08, 2022 17:08
KeithW wrote: Thu Jan 06, 2022 18:22
skiddaw05 wrote: Thu Jan 06, 2022 13:11 I've sometimes wondered this about that even rarer beast, the rural S4
I know of some in the North East - here is one to start with
https://www.google.co.uk/maps/@54.58910 ... 8192?hl=en
I thought you were going to mention Marton Road, or is it S2+2 because of the white paint down the centre?
https://goo.gl/maps/wtD9WHL3vPFrn47B8
It's such penny pinching on roads like this, to save on kerbs usually. These would be ideal locations for some SUDS and/or planting to break up the asphalt ribbons somewhat.
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
AlexBr967
Member
Posts: 131
Joined: Sat Jan 11, 2020 21:08

Re: Why does the UK not have any D2+1 roads?

Post by AlexBr967 »

Surprised no-one has mentioned the M3 through Thorpe Interchange yet: https://goo.gl/maps/ZV56SMzz3qU5Pya17
To be fair though it's technically D2M+1 not D2+1
User avatar
KeithW
Member
Posts: 19205
Joined: Thu Dec 04, 2014 13:25
Location: Marton-In-Cleveland North Yorks

Re: Why does the UK not have any D2+1 roads?

Post by KeithW »

Big Nick wrote: Sat Jan 08, 2022 17:08 I thought you were going to mention Marton Road, or is it S2+2 because of the white paint down the centre?
https://goo.gl/maps/wtD9WHL3vPFrn47B8
Well its not rural or NSL and its just a short section past the hospitals (Roseberry Park and James Cook). There may be 4 lanes but its not used as a typical 4 lane road. the off side lane heading in to town is best avoided as you will almost always get stuck behind someone making a right turn.
User avatar
KeithW
Member
Posts: 19205
Joined: Thu Dec 04, 2014 13:25
Location: Marton-In-Cleveland North Yorks

Re: Why does the UK not have any D2+1 roads?

Post by KeithW »

Bryn666 wrote: Sat Jan 08, 2022 19:04
Big Nick wrote: Sat Jan 08, 2022 17:08
KeithW wrote: Thu Jan 06, 2022 18:22


I know of some in the North East - here is one to start with
https://www.google.co.uk/maps/@54.58910 ... 8192?hl=en
I thought you were going to mention Marton Road, or is it S2+2 because of the white paint down the centre?
https://goo.gl/maps/wtD9WHL3vPFrn47B8
It's such penny pinching on roads like this, to save on kerbs usually. These would be ideal locations for some SUDS and/or planting to break up the asphalt ribbons somewhat.
Not on Marton Road you wouldnt, its carrying 25k of traffic and a lot of it is going in an out of the hospitals. Its horribly overcrowded as it handles both local traffic and outbound traffic for the A174 Parkway, A19, Stokesley, Guisborough and Whitby. The road is pretty much the same as it was in the 1950's but now handles 10 times the volume of traffic. Farther south where it drops to 2 lanes there is some planting and grass verges but since that is the latest development hot spot that wont last.
https://www.google.co.uk/maps/@54.51995 ... 8192?hl=en
User avatar
Bryn666
Elected Committee Member
Posts: 35755
Joined: Thu Jun 20, 2002 20:54
Contact:

Re: Why does the UK not have any D2+1 roads?

Post by Bryn666 »

KeithW wrote: Sat Jan 08, 2022 20:57
Bryn666 wrote: Sat Jan 08, 2022 19:04
Big Nick wrote: Sat Jan 08, 2022 17:08

I thought you were going to mention Marton Road, or is it S2+2 because of the white paint down the centre?
https://goo.gl/maps/wtD9WHL3vPFrn47B8
It's such penny pinching on roads like this, to save on kerbs usually. These would be ideal locations for some SUDS and/or planting to break up the asphalt ribbons somewhat.
Not on Marton Road you wouldnt, its carrying 25k of traffic and a lot of it is going in an out of the hospitals. Its horribly overcrowded as it handles both local traffic and outbound traffic for the A174 Parkway, A19, Stokesley, Guisborough and Whitby. The road is pretty much the same as it was in the 1950's but now handles 10 times the volume of traffic. Farther south where it drops to 2 lanes there is some planting and grass verges but since that is the latest development hot spot that wont last.
https://www.google.co.uk/maps/@54.51995 ... 8192?hl=en
How does replacing painted hatching with no turnings as per the link Nick shared with sustainable drainage and planting/landscaping remove any road capacity? It doesn't.
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
KeithW
Member
Posts: 19205
Joined: Thu Dec 04, 2014 13:25
Location: Marton-In-Cleveland North Yorks

Re: Why does the UK not have any D2+1 roads?

Post by KeithW »

Bryn666 wrote: Sat Jan 08, 2022 21:27
How does replacing painted hatching with no turnings as per the link Nick shared with sustainable drainage and planting/landscaping remove any road capacity? It doesn't.
Given that the road is the main access for 2 hospitals and housing estates where thousands of people live there is a phrase about the cure being worse than the disease that applies here. The ONLY road access to James Cook hospital which is the main hospital south of the Tees and the Regional Trauma Unit is via Marton Road with the exception of the back road from Ladgate Lane via the staff car park.

95% of traffic including ambulances have to turn here.
https://www.google.co.uk/maps/@54.55026 ... !1e3?hl=en

If live in Easterside you have to turn here.
https://www.google.co.uk/maps/@54.55236 ... 8192?hl=en

Back in the late 1970's and 1980's there was a plan to build a new Middlesbrough bypass along Ormesby Beck here but it was cancelled. They did throw us a token development in the form of a railway halt on the Esk Valley Railway. https://www.gazettelive.co.uk/news/tees ... ong-973595

Given that I live in Marton just 200m from Marton Road I am rather familiar with the issue. To nobody's surprise the 'solution' described below made little difference.
https://www.gazettelive.co.uk/news/tees ... n-16632375

To make matters worse even more plans for more new housing developments have been submitted.
https://www.gazettelive.co.uk/news/tees ... r-22669692

The Northern end of the bypass was built but has nothing to plug into so just fizzles out at this roundabout.
https://www.google.co.uk/maps/@54.56736 ... 8192?hl=en
User avatar
Chris5156
Deputy Treasurer
Posts: 16908
Joined: Thu Sep 06, 2001 21:50
Location: Hampshire
Contact:

Re: Why does the UK not have any D2+1 roads?

Post by Chris5156 »

KeithW wrote: Sun Jan 09, 2022 11:07
Bryn666 wrote: Sat Jan 08, 2022 21:27
How does replacing painted hatching with no turnings as per the link Nick shared with sustainable drainage and planting/landscaping remove any road capacity? It doesn't.
Given that the road is the main access for 2 hospitals and housing estates where thousands of people live there is a phrase about the cure being worse than the disease that applies here. The ONLY road access to James Cook hospital which is the main hospital south of the Tees and the Regional Trauma Unit is via Marton Road with the exception of the back road from Ladgate Lane via the staff car park.

95% of traffic including ambulances have to turn here.
https://www.google.co.uk/maps/@54.55026 ... !1e3?hl=en

If live in Easterside you have to turn here.
https://www.google.co.uk/maps/@54.55236 ... 8192?hl=en
Neither of which would be affected by Bryn's suggestion about painted hatching in the middle of the road that serves no purpose!
User avatar
KeithW
Member
Posts: 19205
Joined: Thu Dec 04, 2014 13:25
Location: Marton-In-Cleveland North Yorks

Re: Why does the UK not have any D2+1 roads?

Post by KeithW »

Chris5156 wrote: Sun Jan 09, 2022 11:10
Neither of which would be affected by Bryn's suggestion about painted hatching in the middle of the road that serves no purpose!
It serves the precise purpose describe in the Highway Code.

Specifically when the road was widened at the entrance to James Cook Hospital and the pedestrian crossing here added some users, mainly bikers would drive down what they perceived as a middle lane and that try and force their way in to the traffic stream here.
https://www.google.co.uk/maps/@54.55054 ... 8192?hl=en

Given that Middlesbrough Council Highways Dept is ALWAYS strapped for cash it was decided that spending money on fixing potholes was better use of its resources than adding planters. As for sustainable drainage that actually runs into Ormesby Beck. In fact there is a major action for this financial year to clear some of the blocked surface drains.
Image
https://www.middlesbrough.gov.uk/enviro ... ood-scheme

Further up the A172 we have had added some planters paid for by the Marton West Community Council.
https://www.google.co.uk/maps/@54.53188 ... 8192?hl=en
User avatar
nowster
Treasurer
Posts: 14803
Joined: Tue Aug 31, 2004 16:06
Location: Manchester

Re: Why does the UK not have any D2+1 roads?

Post by nowster »

Given it's a broken line on the striped section, overtaking within it is not forbidden. It might help a little for emergency services access for the nearby hospital. Given its short length, it's really not worth the expense and future maintenance costs. Who knows what runs under the centre of the road? If there's a sewer, planting trees would be a very bad idea.
User avatar
KeithW
Member
Posts: 19205
Joined: Thu Dec 04, 2014 13:25
Location: Marton-In-Cleveland North Yorks

Re: Why does the UK not have any D2+1 roads?

Post by KeithW »

nowster wrote: Sun Jan 09, 2022 12:48 Given it's a broken line on the striped section, overtaking within it is not forbidden. It might help a little for emergency services access for the nearby hospital. Given its short length, it's really not worth the expense and future maintenance costs. Who knows what runs under the centre of the road? If there's a sewer, planting trees would be a very bad idea.
In fact when the road is at its busiest the hatched area is used by ambulances especially if the air ambulance is busy elsewhere. I dont think there is a sewer down there as that part of Marton Road was semi-rural in the 1950's when it was the main route to the South.
https://www.sabre-roads.org.uk/maps/ind ... 15&layer=4
User avatar
dereer
Member
Posts: 200
Joined: Wed Nov 23, 2016 18:51
Location: County Monaghan, Ireland
Contact:

Re: Why does the UK not have any D2+1 roads?

Post by dereer »

I live near the D2+1 section of the N2 in Castleblayney and I feel that D2+1s are fundamentally flawed.

First of the issues is that one slow vehicle can delay everyone else very easily if it happens to be met on a one lane section. At least on a WS2, there are hard shoulders that slow vehicles can (and usually do) pull into to let others past. Even on narrower roads there tends to be less distance where it is impossible to overtake. I've lost track of how many tractors I've gotten stuck behind on that road.

Similarly, one breakdown can cause the road to get blocked in one direction if it happens on a one lane section (this has already been mentioned). This is a very major issue and one that is only really an issue an a D2+1. (It could be an issue on an S1 but most of those get so little traffic as for it to be a non-issue.) This also extends to verge cutting, where the entire road needs to be closed just for cutting grass. (On most S2s the verge cutting can just be driven around and on S1s they tend to be locals who will reverse into a driveway to let people through.)

In addition, many drivers dangerously overtake very close to the end of the 2 lane section, causing many near misses. I have witnessed many myself on that bit of the N2 (thankfully no actual crashes though) and it was a significant factor to the NRA stopping the construction of D2+1s.

Factors like these are almost certainly reasons why D2+1 roads aren't really a thing in the UK, as they have major drawbacks and are usually not suitable for significant amounts of traffic.
it/he/they | aka computerfan0
My travelled roads can be found here.
Post Reply