A30 Carland Cross Chiverton Cross

[adam 1972]

Nice pics, thanks for posting.
Is that Chybucca overbridge ?
If so they are making good progress

[roadphotos]

Here's another picture of the construction of the overbridge at the Chybucca Junction

[roadphotos]

The B3284 has been diverted around the Chybucca Junction works. Here's some pictures. When the new A30 is complete the B3284 will be rerouted again to meet the A30:at the new junction.

[adam 1972]

Thanks, certainly a lot of progress on the bridge, I did drive through the temporary B3284 a couple of weeks ago, seems to have been quite a bit of progress even since then.

Did you get a chance to see what is going on on the other side of the A30 north of the bridge construction ?
From recent satellite images it looks as if there are some earthworks going on, possibly for the new slips roads, new B3284, and the original traffic management plan indicates a temporary alignment to allow the construction of the northern roundabout.

[roadphotos]

There are works on both sides of the existing A30 at the Chybucca Junction site, I'm guessing that this is to accommodate the dualled A30, the new rerouted B3284 (via the new junction) and the link from the new junction to what will be the old A30. So far the existing A30 hasn't changed but it may be routed around the works as construction continues.

[roadphotos]

The existing A30 Zelah By-Pass. The dual carriageway will run alongside it.

[RichardEvans67]

by adam 1972 » Thu Feb 03, 2022 14:07

A30 Traffic Management Alert
12 Month closure of Pennycomequick Lane

I find it quite surprising that they need to close the lane for such a long period of time. The new bridge here is away from the current lane. So I would have have expected building the bridge while the lane is still open. Then a short term closure to tie in the lane to the new alignment.

I suppose it makes it easier just to close the whole thing, and perhaps the traffic levels are too low to justify going to any more trouble. I would think it would still be a major pain for the locals.

[RichardEvans67]

by roadphotos » Thu Feb 03, 2022 17:12

Here's another picture of the construction of the overbridge at the Chybucca Junction

Thanks for the pictures.

What I can see of the Chybacca overbridge seems to be something interesting that I haven't seen before. It seems to have retaining walls in front of the bridge peers. So it looks as though the much of the length of the bridge peers will be buried under embankments. It will be interesting to see what it looks like when it finished.

[jackal]

What I can see of the Chybacca overbridge seems to be something interesting that I haven't seen before. It seems to have retaining walls in front of the bridge peers. So it looks as though the much of the length of the bridge peers will be buried under embankments. It will be interesting to see what it looks like when it finished.

I've not seen what you're talking about, but if it's eastbound under the GSJ that's for a drainage culvert. PDF p. 7: https://infrastructure.planninginspecto ... e%206).pdf

[adam 1972]

Traffic Management Alert

A30 Chiverton to Carland Cross - Temporary 2 week 24/7 closure B3284 North at Chybucca

Costain, on behalf of Highways England, is working on the A30 Chiverton to Carland Cross road improvement scheme and will be temporarily closing the B3284 North, for drainage and other works to take place.

The B3284 North will close temporarily for all through traffic from the A3075 to Chybucca, except for residents, for 2 weeks 24/7 from Monday the 21 February at 9:00am (09:00hrs) to Saturday the 5 March 2022 at 6:00am (06:00hrs).

It will reopen on Saturday the 5 March 2022 at 6:00am.

Diversion route https://mcusercontent.com/1d4eb632df7c9 ... 95db05.jpg

[RichardEvans67]

by jackal » Fri Feb 04, 2022 10:41

I've not seen what you're talking about, but if it's eastbound under the GSJ that's for a drainage culvert. PDF p. 7:

You can see it in some of the picture uploaded above if you look closely.
(such as this one download/file.php?id=20260&mode=view). Nothing to do with drainage culverts. They are the vertical peers that will take a lot of the weight. Earlier pictures on Google Earth street view, show the bridge peers before the retaining walls and fill.

Some of the pictures above now show retaining walls, that will presumably be at the edged of the carriageways, with the bridge peers outside them. So presumably the fill will be covering the bottom part of the peers. Obviously they built the peers before they did that, as they need to take the load down to the foundations.

Edit :
This perhaps shows more clearly what I mean.
download/file.php?id=20258&mode=view
If you look Centre Right. The peers are clearly behind a retaining wall, and fill behind the retaining wall is covering the lower part of the peers.

I'm not saying it is unusual, I'm just saying I haven't seen it before.

[Herned]

I agree it definitely looks like there is a retaining wall in front of the piles for the bridge deck. That does seem unusual

[BF2142]

What’s the reason for the embankment clearance and the works on the shoulder on the Zelah bypass? I didn’t think the new road affected the existing road?

[jackal]

What’s the reason for the embankment clearance and the works on the shoulder on the Zelah bypass? I didn’t think the new road affected the existing road?

There are lots of works in the vicinity of the existing road at Zelah and part of it is realigned:

https://infrastructure.planninginspecto ... 206%29.pdf

[RichardEvans67]

by BF2142 » Sat Feb 05, 2022 11:41

What’s the reason for the embankment clearance and the works on the shoulder on the Zelah bypass? I didn’t think the new road affected the existing road?

At the eastern end of the Zelah bypass, the existing A30 keeps it's existing alignment, and the new D2 is alongside (on the south side). However as you go further west, things start to be realigned. By the time you get to the 2 barrow bridge (west of Zelah), the new D2 is on the existing alignment, (to use that bridge) with a new local route to the north of it (to replace the existing A30).

The realignment starts to happen some way east of the accommodation bridge over the Zelah Bypass. So at that bridge site the existing A30 is realigned somewhat. Also that bridge is having to be replaced, so presumably there is quite a lot of clearance work to prepare for building the new bridge.

On the Zelah bypass west of the accommodation bridge, the new D2 will be part way through adjusting onto the existing alignment. Also presumably the new D2 is wider than the existing A30. So presumably that shoulder will need to be moved back. The other shoulder will probably also need moving to make way for the new local route.

[Ruperts Trooper]

For those using this stretch, how is traffic coping presently with the roadworks? I'm due to go through on March 6/7.

[roadphotos]

So far the roadworks haven't really had any affect on the existing traffic flows as much of the new A30 is being constructed offline of the existing road. There is a 50mph limit on the Zelah By-Pass but traffic appears to be ok through there. You will get the usual traffic jams along this part of the A30 once the holiday season starts but that's the same every year (hence why a new road is needed). Last summer my sat nav often told me that it would be an hour and a half to clear this section of the A30 so I often had to divert via Truro or Perranporth but these delays have nothing to do with the roadworks it's just simply the shear volume of traffic in the holiday season especially last year due to more people coming to Cornwall instead of traveling abroad due to Covid.

[Ruperts Trooper]

So far the roadworks haven't really had any affect on the existing traffic flows as much of the new A30 is being constructed offline of the existing road. There is a 50mph limit on the Zelah By-Pass but traffic appears to be ok through there. You will get the usual traffic jams along this part of the A30 once the holiday season starts but that's the same every year (hence why a new road is needed). Last summer my sat nav often told me that it would be an hour and a half to clear this section of the A30 so I often had to divert via Truro or Perranporth but these delays have nothing to do with the roadworks it's just simply the shear volume of traffic in the holiday season especially last year due to more people coming to Cornwall instead of traveling abroad due to Covid.

Thanks for that - I'm well aware of the level of seasonal traffic, having been part of it several times - I'm hoping my early March timing will avoid that.

[crowntown100]

I've been through a few times in the last month or so and progress does seem to have ramped up in that time. There doesn't seem to be a great deal going on at the Carland Cross side at the moment, although I've only been through in the dark in the last few weeks so that may have changed as I see they've added a temporary speed limit around there. It's strange approaching Chiverton Cross from Redruth and seeing the trees have been cut down on a large portion of the island, but it does make it easier to see circulating traffic, so that's a bonus.

I agree it definitely looks like there is a retaining wall in front of the piles for the bridge deck. That does seem unusual

They did the same at Temple when that was being built. I guess the piles hold the weight of the bridge, and the retaining wall is just there for... well, retaining

I haven't seen whether this is correct or not so this is purely speculation, but I imagine that they will build what will become the LARs over the bridge and divert traffic to use the new junction, less the sliproads, so that they can complete tie in works and building the new road under the bridge without disrupting the traffic still on the A30.

[adam 1972]

I haven't seen whether this is correct or not so this is purely speculation, but I imagine that they will build what will become the LARs over the bridge and divert traffic to use the new junction, less the sliproads, so that they can complete tie in works and building the new road under the bridge without disrupting the traffic still on the A30.

According to the traffic management plans you could be pretty spot on there, they mention a temporary alignment to the north to allow construction of the northern roundabout, then once both roundabouts and the bridge are complete A30 through traffic will use the new junction, with the B3284 south accessed from the southern roundabout and the B3284 north from the northern roundabout, allowing the new D2 to be built under the bridge and also the tie in works, but having said that traffic management plans can change.