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fras wrote: ↑Wed Jun 30, 2021 10:58
Having now had a look at "the manual", it seems that the key word is "relaxations". This is where one can deviate from what the formulae come up with. Clearly this is optional, so one does wonder whether the option is ever taken up, because officialdom always likes to be able to say "its all as per the design manual", whereas if one relaxes the standard, you can always be criticised if something untoward comes up later on.
The standard is for dual carriageways to be designed for 120 km/h. In order to build a dual carriageway in the Clydach gorge, the designers have deviated from the standard in the manual. They have done this by designing the road for a lower top speed, as otherwise the financial and environmental costs would be too high.
So your choice is spending much more money just so you can drive slightly faster - the difference over the 5 miles of this section between 50mph and 70mph is 42 seconds, or putting up with it. You would need to prove that spending that money was more worthwhile than using it to build the section of the road.
Once you have decided to design a road to a particular limit, this means that whilst it is possible to physically drive faster, it would be very stupid to sign it for faster speeds than the visibility allows. For what I should hope are obvious reasons
fras wrote: ↑Wed Jun 30, 2021 10:58
Having now had a look at "the manual", it seems that the key word is "relaxations". This is where one can deviate from what the formulae come up with. Clearly this is optional, so one does wonder whether the option is ever taken up, because officialdom always likes to be able to say "its all as per the design manual", whereas if one relaxes the standard, you can always be criticised if something untoward comes up later on.
The standard is for dual carriageways to be designed for 120 km/h. In order to build a dual carriageway in the Clydach gorge, the designers have deviated from the standard in the manual. They have done this by designing the road for a lower top speed, as otherwise the financial and environmental costs would be too high.
So your choice is spending much more money just so you can drive slightly faster - the difference over the 5 miles of this section between 50mph and 70mph is 42 seconds, or putting up with it. You would need to prove that spending that money was more worthwhile than using it to build the section of the road.
Once you have decided to design a road to a particular limit, this means that whilst it is possible to physically drive faster, it would be very stupid to sign it for faster speeds than the visibility allows. For what I should hope are obvious reasons
If I'm ever down that way, I'll make sure I have a tootle along the new section.
It's open! Just drove through this morning and was pleasantly surprised to find both lanes of both carriageways open; all cones and temporary speed limits gone. I hadn't seen any news about it opening. I shall have to take some completion photos soon!
jeremai wrote: ↑Fri Dec 03, 2021 08:54
It's open! Just drove through this morning and was pleasantly surprised to find both lanes of both carriageways open; all cones and temporary speed limits gone. I hadn't seen any news about it opening. I shall have to take some completion photos soon!
Yes, its complete
I took a video of it yesterday, starting off at Beaufort and joining the A465 at the top of Brynmawr, down to the Llanelly hill GSJ back up the last section over the gateway bridge and back down towards Abergavenny. https://youtu.be/MXKIqa9fpbU (The video will be 4k when it has finished processing)
Thanks for the video, I see why it's 50mph does seem not the best sightlines in places.
When Dowlais Top to Hirwaun is completed I wonder if Swansea will be sign A40 (A465) at Raglan and conversely The Midlands A465 (M50) from Junctions 42/43 of the M4. It seems 12 miles shorter and will all be HGDC.
A pragmatic yet beautiful piece of work. A D2ALR ! - cautiously speed-limited, with a few accessible verges (and bus stops ), excellently lit, signed and engineered. It was one of my favourite roads when it was built in the 1960's, even as a fully-permissive S3 - a format I soon came to abhor.
Thanks for the video, I see why it's 50mph does seem not the best sightlines in places.
When Dowlais Top to Hirwaun is completed I wonder if Swansea will be sign A40 (A465) at Raglan and conversely The Midlands A465 (M50) from Junctions 42/43 of the M4. It seems 12 miles shorter and will all be HGDC.
I'm also curious to see if M4 levels reduce?
It would be nice if this was the case. It definitely should take some stress off the M4 at Newport which has been exacerbated by scrapping the tolls on the Severn Bridges.
Bryn Terminally cynical, unimpressed, and nearly Middle Age already. She said life was like a motorway; dull, grey, and long.
Also, in this age of emissions savings etc, despite the climb up to the Heads, I still think it's madness that traffic heading northeast has had to travel to southeast Wales all this time to stay on a reasonable route, burning lots of fuel in the process. Connectivity through Wales is really not great in any direction other than due east.
jeremai wrote: ↑Fri Dec 03, 2021 08:54
It's open! Just drove through this morning and was pleasantly surprised to find both lanes of both carriageways open; all cones and temporary speed limits gone. I hadn't seen any news about it opening. I shall have to take some completion photos soon!
Yes, its complete
I took a video of it yesterday, starting off at Beaufort and joining the A465 at the top of Brynmawr, down to the Llanelly hill GSJ back up the last section over the gateway bridge and back down towards Abergavenny. https://youtu.be/MXKIqa9fpbU (The video will be 4k when it has finished processing)
I drove along this road on Thursday morning too! I looked to see if my car was there, but without luck. I remember I followed at a distance a blue lorry registered in the Netherlands through the 50mph section. I gained on him after the Brynmawr turn where the NSL comes in and then I turned left at the top of the hill for Ebbw Vale in the lane drop whilst he went straight on. There is a blue lorry heading west that could be the one I saw, but it can be seen only a few seconds before the end of the video where you are heading east, so I don't know if I was about to appear. I do remember the blue Honda Civic parked on the Brynmawr turn as I went past and I wondered why he had stopped there and it's there when you turn off, so we must have passed at similar times.
This is off topic, but living in Brecon, I don't normally use this section of the A465. I had a hospital appointment on Thursday morning and turned up at Nevill Hall Hospital at the correct time, only to be told I was in the wrong hospital as the letter said I should go to Ebbw Vale, so that's the reason I needed this road on Thursday. The staff at both hospitals were very understanding and Ebbw Vale fitted me in at a later time, so full praise to them. In my mitigation, both letters started with Aneurin Bevan Hospital. I've had many hospital outpatients appointments over the last few years and they've all been at Abergavenny (I was there only two days before this on Tuesday) and so I only looked at the time and date of my appointment and not at which hospital I needed to attend. Needless to say, I'll check this carefully next time!
Thanks for that. Unfortunately I didn't get any decent landscape oriented pictures from the mountain so I've submitted the first picture with the bridge and the curves.
Bryn666 wrote: ↑Sat Dec 11, 2021 18:45
Cracking photos. Sadly it's going to be new year before I can get near Wales.
I had cause to drive from Barry to Monmouth a few days ago, but couldn't go this way as I just can't bear the exorbitant cost of the extra petrol to climb up to the Heads at the moment. Really disappointing, don't know when it'll be economical again to take a diversion that way, if ever.
As an aside, I might be crazy (and my car might be lying to me) but fuel doesn't seem to go very far lately on the Bristol-Barry drives. Even though I've been trundling along at pretty much my best economy speed instead of 70.
jeremai wrote: ↑Sat Dec 11, 2021 17:33
Some completion photos along the route from yesterday.
Brynmawr is my new favourite GSJ in the country. There's just so much going on. The signature bridge, the split level mainline, the braiding to resolve the vertical alignment. It's more like something you'd see in Italy than the UK.
And yes, this or the last one of the set would have to be odds on for photo of the month if entered.
The problem with my last photo is it's portrait oriented so you'd only see a tiny bit of it on the banner. As you walk around the side of that hill the road stretches out from west to east, lending itself to a landscape photo, but unfortunately there are power lines and pylons that get in the way!
Speaking of the Gateway bridge, it's still not open to pedestrians yet which was disappointing, but I guess I still have that to look forward to!