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The government announced that the preferred solution was for a smart motorway with “All Lane Running”. This means the existing hard shoulder would be converted into a traffic lane providing 3 lanes for traffic. Regular refuge areas are available in place of the hard shoulder for emergency use.
As part of this we will assess a wide range of information about the road to establish the nature of the current problems. This will help us develop an outline design concept and determine the Smart Motorway operating system best suited to this section of road. We aim to complete this first design stage by the end of May 2017.
They are still aiming for a March 2020 start, apparently.
I was wondering what is the gradient northbound from Welwyn, as the congestion caused by traffic joining does not clear until the brow of the hill.
Also what is the life expectancy for bridges and other "permanent" structures as this section is already approaching 55 years old and would be over 60 by the time it is fully reopened as a D3(sM). ( Does SABRE have an official designation for all lane running motorways? )
“The simple step of a courageous individual is not to take part in the lie" - Aleksandr I. Solzhenitsyn
Johnny Mo
mikehindsonevans wrote:... as has been proven by the Victorian railway engineers, whose legacy (from the mid-1860s) is only threatened by aberrant growths of buddleia!
There is a massive difference between Victorian engineering, where the engineer was king and the aim was to deliver the best possible railway. Against an early 60's motorway where the accountant was king and the political masters were interested in short term targets ( such as 1000 Miles of new motorway in 5 years ).
At least the A1(M) does have continuous hard shoulders unlike the M50 from the same era.
“The simple step of a courageous individual is not to take part in the lie" - Aleksandr I. Solzhenitsyn
Johnny Mo
I'm struggling to understand why this scheme was promoted. Surely it has to be poor value for money?? When you have an 'isolated' piece of D2M on an otherwise D3M motorway, why not simply upgrade it fully??
If we took this a step further, the M5 would never have been widened, just 'smartened' instead. And yes, I'm thinking it mightn't be particularly long before the bridges would be due for replacement.
Will be interesting to see how this works out as the first D3 smart motorway, with less lanes for traffic to move into if there is an lane closure than a D4. Another point is why the big difference in possible costs £109.7m to £156.1m and how much more would it cost to add hard shoulders? Possible not a whole lot more even though HE save time without a planning process.
Berk wrote:I'm struggling to understand why this scheme was promoted. Surely it has to be poor value for money?? When you have an 'isolated' piece of D2M on an otherwise D3M motorway, why not simply upgrade it fully??.
I would guess because it is politically more difficult to do "motorway widening" in this area with compulsory purchases than it is to "convert the road to smart motorway as part of a national programme of upgrades" which can mainly be done within the existing highway boundary.
Berk wrote:I'm struggling to understand why this scheme was promoted. Surely it has to be poor value for money?? When you have an 'isolated' piece of D2M on an otherwise D3M motorway, why not simply upgrade it fully??.
I would guess because it is politically more difficult to do "motorway widening" in this area with compulsory purchases than it is to "convert the road to smart motorway as part of a national programme of upgrades" which can mainly be done within the existing highway boundary.
But it would be far better value for money in the long run to upgrade this bit "properly". Like I say, it would be like 'smartening' the M5, if it hadn't been widened in the 80s.
And as someone else said, if the cost run into £100m's per mile, I would far rather my taxes were used to provide a permanent, 24/7 lane than a shonky ALR-style lane gain/drop arrangement.
Berk wrote:I'm struggling to understand why this scheme was promoted. Surely it has to be poor value for money?? When you have an 'isolated' piece of D2M on an otherwise D3M motorway, why not simply upgrade it fully??.
I would guess because it is politically more difficult to do "motorway widening" in this area with compulsory purchases than it is to "convert the road to smart motorway as part of a national programme of upgrades" which can mainly be done within the existing highway boundary.
But it would be far better value for money in the long run to upgrade this bit "properly". Like I say, it would be like 'smartening' the M5, if it hadn't been widened in the 80s.
And as someone else said, if the cost run into £100m's per mile, I would far rather my taxes were used to provide a permanent, 24/7 lane than a shonky ALR-style lane gain/drop arrangement.
The roadworks would cause very bad bottlenecks if widening were to occur.
Though roads may not put a smile on everyone's face, there is one road that always will: the road to home.
Looks like the "widening" to D3ALR has the go ahead and will start in March 2020 but the costs are quite expensive at £170m for only 7 miles! Don't suppose how much more a full widening job would have cost, surely not much.
Key points with the scheme is will we have ALR running through the junctions, at J7 probably but junction 8 looks tight considering the proximity of the ECML bridge south of the junction.
Also will be interesting to see whether J4 to J1 & J8 to J9 will be in need of widening soon (before 2030), as traffic moves more freely from Welwyn to Stevenage.
My guess is that widening would have been particularly expensive and controversial as they would have needed to purchase a lot of expensive residential land, especially between 6 and 7. The settlements just north of 6 are expensive areas even by Hertfordshire standards. Stevenage industrial estate is also very close to the southbound carriageway between 7 and 8.
Also will be interesting to see whether J4 to J1 & J8 to J9 will be in need of widening soon (before 2030), as traffic moves more freely from Welwyn to Stevenage.
thatapanydude wrote: ↑Fri Nov 30, 2018 01:42
Looks like the "widening" to D3ALR has the go ahead and will start in March 2020 but the costs are quite expensive at £170m for only 7 miles! Don't suppose how much more a full widening job would have cost, surely not much.
Key points with the scheme is will we have ALR running through the junctions, at J7 probably but junction 8 looks tight considering the proximity of the ECML bridge south of the junction.
Also will be interesting to see whether J4 to J1 & J8 to J9 will be in need of widening soon (before 2030), as traffic moves more freely from Welwyn to Stevenage.
J1-4 is at about 70k AADT so already in need of widening really.
HE have a set budget and could do at most half of current widening if they provided a HS every time. Earthworks, bridge replacement and land itself (especially in SE England) are not cheap. Frankly the existing level of widening is not enough to keep up with need (J1-4 is a case in point) so I wouldn't want to see it dramatically cut back for the sake of hard shoulders.
I'm glad this precedent is being set; there are plenty of 'short' bits of heritage D2M that need widening but will never get it in the current climate. Traffic flow at the M5/M4 interchange could benefit greatly from extension of the ALR on the M4 towards the Severn and this shows willing for D3ALR to be used.
thatapanydude wrote: ↑Fri Nov 30, 2018 01:42
Key points with the scheme is will we have ALR running through the junctions, at J7 probably but junction 8 looks tight considering the proximity of the ECML bridge south of the junction.
I'm hoping that there will be a lane drop through the junctions, especially at J8. There is a lot of traffic leaving the A1 southbound at J8, and in the mornings this traffic regularly queues for a mile or two in lane 1. If there was no lane drop then that queue would probably move to the hard shoulder, which is not desirable. The root of the problem is the sheer amount of traffic trying to enter Stevenage on the A602: even if J8 was improved (which it could be) the A602 itself is over capacity so there's nothing you can do to stop the queuing on the approach to the junction.
Admittedly, sometimes there are queues on the southbound A1(M) in lanes 2 and 3 as well. But I don't believe this is because of the lane drop - it seems to be due to traffic queuing all the way back from J7 where a lot of traffic joins.
I agree with your analysis of traffic patterns there. The solution might, however be to increase Stacking space ay the junctions to maintain the main line through ...