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#71
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Latest Heathrow master plan
tim... wrote:
"Recliner" wrote in message ... On Wed, 19 Jun 2019 12:43:48 +0100, "Clive D.W. Feather" wrote: In article , Roland Perry writes The only disruption will come at the end, when the traffic is diverted to the new route. My guess is that the northbound traffic will be moved first, with a few weeks of lane 1 closures required while they connect the new to the old carriageways, then an overnight closure for the final switch to be made. The same procedure would then be followed a few months later to divert the southbound carriageway to the new alignment. The amount of work you would be expecting them to do "overnight" beggars belief. I disagree. Build the two new carriageways. At each end, cut them off very close to the edge of northbound lane 1 (there's no hard shoulder, right? if there is, adjust description accordingly). Cone off northbound lane 1. Spend a week or two filling in the narrow gap between the old and new northbounds at each end. Not sure that you even need a closure to switch over. Simply move all the cones. Repeat for the southbound (though this time you're closing lane 4). Yes, that's what I'm expecting. I have never in my life seen construction companies do this even when the new road is well away from the old route It costs millions extra to do it that way Why would it cost any extra? You have a completely segregated work site to the west of the existing road, to build the new, lowered carriageways, with runway and taxiway bridges. This might take 2-3 years, and won't affect the existing motorway, except for a few lane closures while a safety wall is built between the existing northbound carriageway and the work site. When the new carriageway is ready, you need to close lane 1 of the old northbound carriageway for a few weeks while the physical connection of the road surfaces is made, and then an overnight closure for first the M4-bound traffic to be diverted, and then again when the through traffic is switched. A few months later, a similar process is used to connect the southbound. It won't be nearly as disruptive as when the M25 was widened to 12 lanes in the area. |
#72
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Latest Heathrow master plan
In article , tim...
writes I have never in my life seen construction companies do this even when the new road is well away from the old route It costs millions extra to do it that way Come and look at the A14 rebuild between Girton and Swavesey. It's being done in a similar way. -- Clive D.W. Feather |
#73
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Latest Heathrow master plan
In article , tim...
writes If you think that they can link a new route into a current motorways by only diverting traffic for a few weeks then you have never seen how they do this They're doing it where I live. IME they narrow the road where the connection is to be made for the full term of the works. They do this because they need access to the new road for construction vehicles - how else are they going to build it? Haul roads. That's what they use here. They have narrowed the A14, I accept, but that's because they're also doing stuff along the existing verges. -- Clive D.W. Feather |
#74
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Latest Heathrow master plan
In message , at 21:07:58 on Wed, 19 Jun
2019, Clive D.W. Feather remarked: I have never in my life seen construction companies do this even when the new road is well away from the old route It costs millions extra to do it that way Come and look at the A14 rebuild between Girton and Swavesey. It's being done in a similar way. And there's only disruption to the through traffic for two isolated overnight periods (while they switch some virtual points)? You have got-to-be-joking. -- Roland Perry |
#75
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Latest Heathrow master plan
In message , at 21:07:04 on Wed, 19 Jun
2019, Clive D.W. Feather remarked: In article , Roland Perry writes Presumably all the rerouting of traffic on the A14 project is going swimmingly, to a similar plan? All the bits I've seen have been. For example, the new temporary northwestbound entry slip at Bar Hill was done that way. There's lots of bits of new carriageway waiting to be connected (e.g. northwestbound between the services north of Bar Hill and the Swavesey intersection, though I think that's waiting for the Lolworth bridge to be completed). Or, for another example, the diversion of the westbound A14 loop on to the M11 (or possibly temporarily-not-M11). Or the diversion of the northwestbound A1307 between Girton and the new Dry Drayton roundabout. You are obviously familiar with a completely different A14 to the one where I've endured [Milton to Girton] numerous lane and carriageway closures, contraflows, and other such disruption, for what's got to be two years now. Luckily I don't have much reason to travel Girton the Huntingdon, but I'm sure that's just as chaotic. -- Roland Perry |
#76
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Latest Heathrow master plan
Roland Perry wrote:
In message , at 20:09:11 on Wed, 19 Jun 2019, Basil Jet remarked: I currently do have sight problems but that diagram clearly shows the slip roads from the new alignment being foul of the existing layout. I'm hoping to go and see the actual documents in the library tomorrow so may get a better idea then. The bridges are all in the centres of the junctions, and the roads in those area are unchanged, unlike the roads on the southern part of the M4 junction or the northern part of the T5 junction. (I'm not counting gantries as bridges.) Talking of gantries; along with lamp-posts, central reservation barriers, and all the other street furniture, they'd have to be removed along the affected stretches to make the "set of points, with road cones swapping the flow overnight" operation postulated up-thread. Yes, that's true. There would need to be some overnight closures leading up to the actual switch. Some items could be removed well in advance, during other works. Removal of overhead gantries would obviously require overnight closures, but could be done well in advance. Presumably there won't be more than one overhead gantry in each of the shirt connection zones. But quite a lot could be done with just lane closures. For example, the central reservation won't be affected while the northbound carriageway is moved across in two stages. Later, when it's time to move the southbound traffic, much of the structure removal and connection work will be done during closures of the fast lane. The final switchover will require an overnight closure while the 'points are switched'. |
#77
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Latest Heathrow master plan
"Recliner" wrote in message ... tim... wrote: "Recliner" wrote in message ... On Wed, 19 Jun 2019 12:43:48 +0100, "Clive D.W. Feather" wrote: In article , Roland Perry writes The only disruption will come at the end, when the traffic is diverted to the new route. My guess is that the northbound traffic will be moved first, with a few weeks of lane 1 closures required while they connect the new to the old carriageways, then an overnight closure for the final switch to be made. The same procedure would then be followed a few months later to divert the southbound carriageway to the new alignment. The amount of work you would be expecting them to do "overnight" beggars belief. I disagree. Build the two new carriageways. At each end, cut them off very close to the edge of northbound lane 1 (there's no hard shoulder, right? if there is, adjust description accordingly). Cone off northbound lane 1. Spend a week or two filling in the narrow gap between the old and new northbounds at each end. Not sure that you even need a closure to switch over. Simply move all the cones. Repeat for the southbound (though this time you're closing lane 4). Yes, that's what I'm expecting. I have never in my life seen construction companies do this even when the new road is well away from the old route It costs millions extra to do it that way Why would it cost any extra? because you have to build a "throw away" access road to the new build road. The alternative of accessing via the current road is "free" but causes some of that road to need closing |
#78
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Latest Heathrow master plan
"Recliner" wrote in message ... tim... wrote: "Recliner" wrote in message ... On Wed, 19 Jun 2019 10:57:29 +0100, "tim..." wrote: "Recliner" wrote in message ... tim... wrote: "Recliner" wrote in message ... tim... wrote: "Recliner" wrote in message ... https://www.bbc.co.uk/news/business-48668001 well I don't know about the rest, but I for one think that the idea that people who have little or no business at the airport are going to have to suffer 5 years of disruption whilst they rebuild the M25 to create this Hub airport entirely unreasonable Why do you think M25 users will suffer five years of disruption? It's more likely to be a few night time closures or lane restrictions. they are going to put the whole road in a tunnel (presumably from the way it's described not by building a raft on top of it) how can that not cause major disruption? You've obviously not looked at the map, what is "The Map" - I guess there is one, but no I didn't get to see it (You can blame that on my out of date browser if the original article included a link) or read this thread. as one of the first to reply, that would have been difficult If you now read the thread, I pointed out that the buried/bridged motorway will be built on a new alignment, to the west of the current M25, so building it won't disrupt the existing motorway or flights. The plans that I can see show the new road so close that the idea that it wont disrupt the current M25 is fiction. Only the short period of linking the old carriageways and new diversion will cause any disruption, and that should be short (mainly a few days or weeks of lane closures, then a few hours of complete closure while the traffic is switched to the new route). If you think that they can link a new route into a current motorways by only diverting traffic for a few weeks then you have never seen how they do this IME they narrow the road where the connection is to be made for the full term of the works. They do this because they need access to the new road for construction vehicles - how else are they going to build it? They won't need access to the existing M25 to build the new structures to the west — why would they? because they don't helicopter all the construction stuff in, do they tim |
#79
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Latest Heathrow master plan
"Clive D.W. Feather" wrote in message ... In article , tim... writes I have never in my life seen construction companies do this even when the new road is well away from the old route It costs millions extra to do it that way Come and look at the A14 rebuild between Girton and Swavesey. It's being done in a similar way. fortunately, I have no need to travel that way frequently anymore but when i did, the plan was that the exit that I used every day was to be closed in order to facilitate the rebuilt And on the one occasion that I did travel that way, there was certainly cones along the whole of the road closing off lanes and restricted speed limits tim |
#80
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Latest Heathrow master plan
tim... wrote:
"Recliner" wrote in message ... tim... wrote: "Recliner" wrote in message ... On Wed, 19 Jun 2019 12:43:48 +0100, "Clive D.W. Feather" wrote: In article , Roland Perry writes The only disruption will come at the end, when the traffic is diverted to the new route. My guess is that the northbound traffic will be moved first, with a few weeks of lane 1 closures required while they connect the new to the old carriageways, then an overnight closure for the final switch to be made. The same procedure would then be followed a few months later to divert the southbound carriageway to the new alignment. The amount of work you would be expecting them to do "overnight" beggars belief. I disagree. Build the two new carriageways. At each end, cut them off very close to the edge of northbound lane 1 (there's no hard shoulder, right? if there is, adjust description accordingly). Cone off northbound lane 1. Spend a week or two filling in the narrow gap between the old and new northbounds at each end. Not sure that you even need a closure to switch over. Simply move all the cones. Repeat for the southbound (though this time you're closing lane 4). Yes, that's what I'm expecting. I have never in my life seen construction companies do this even when the new road is well away from the old route It costs millions extra to do it that way Why would it cost any extra? because you have to build a "throw away" access road to the new build road. I take it you've never looked at a map of the area, or even Google Maps? The alternative of accessing via the current road is "free" but causes some of that road to need closing There are plenty of other existing roads, including the A4, they can use for access to the work sites. |
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