A428 Black Cat - Caxton Gibbet improvement

[c2R]

I've created a scheme page: https://www.sabre-roads.org.uk/wiki/ind ... ton_Gibbet

[KeithW]

That is from the map, and ignoring the Black Cat interchange. I may have miscounted, but even so it's still nothing put of the ordinary for a route in open countryside.

The costs, excluding the interchange, are much higher than other schemes elsewhere in the UK. I take your point that the costs aren't directly comparable, but there can't be much variation in the cost of building a single overbridge, or moving 1 m3 of earth. Labour costs will be different, but no more than 20% or so.

There must be some explanation

Given that the Black Cat interchange is a major part of the scheme ignoring it is not an option.

The entire scheme is comparable in scope and geology to the A14 upgrade so it should hardly be surprising that the cost is of the same order of magnitude. As with the A14 the scheme has changed somewhat as a result of the consultation. The same basic problems apply, a considerable land take in one of the most expensive parts of England, the need to maintain road, rail and river traffic during construction, a crossing of the ECML and Great Ouse flood plain and the provision of NMU access. As someone who lived close by for the best part of 20 years I am well aware of the tendency of the Great Ouse thereabouts to flood. I am also aware of the fact that there are flooded pits east of the Black Cat as the result of long term gravel excavation. This is not an easy place to build a new strategic road.

Looking at the plans crossing the Great Ouse flood plain requires a significant amount of embankment and of course given the river is navigable an adequate amount of headroom will be required. A quick look at the existing A428 gives some idea of the scale of this.
https://www.google.com.ua/maps/@52.2086 ... authuser=0

When it comes to flooding this is what it looked like at Eaton Socon lock in 2003.


This is what looks like without flooding.
https://www.google.com.ua/maps/@52.2138 ... authuser=0

The there is the addition the new Kelpie Marine access.

[jackal]

There must be some explanation

Even leaving aside Black Cat, most roads don't cross the ECML, or have a viaduct across a flood plain, or so many structures. Earthworks are very substantial due to flooding risks - the western end of the scheme is largely on embankments and seems to have flood bunds on one section. See plans: https://highwaysengland.citizenspace.co ... 0Plans.pdf

And as I mentioned, prices can double or more depending on which factors such as risk, interest, inflation, VAT, etc are included. Consultant costs and other services might be included or excluded. There's really no point in comparing a scheme in Northern Ireland or Wales with one in England unless you're really willing to engage in the forensic accounting necessary to make a like for like comparison, which no one who makes such comparisons ever has from what I've seen.

I've even seen the high cost of big HE schemes compared with the completed A9 section that cost 17 pence per mile or whatever - nevermind that it didn't have any bridges and was less complex than an average local authority bypass in engineering terms.

I'm as disappointed by English road building costs as the next man but they are what they are. £100m+ per mile is completely consistent across recent moderate to complex schemes:

A14
LTC
Stonehenge
A46
A417
A120
A12 widening

Bear in mind as well that the tougher bits of routes tend to be sequenced last. Hence, as routes are now getting finished off, the expensive bits are getting done. The A428 is definitely in that category.

I basically don't see grounds for saying that there's some vast conspiracy between Highways England, DfT, dozens of multinational firms, and various regulators. Not that you said there was but I have seen people go there, and it seems the likely end point of demanding some further explanation when differences in complexity, accounting, sequencing, etc have been set out.

[B1018 A120 M11]

I've posted something similar in the (now ex- ) Oxford-Cambridge expressway thread, so excuse the repetition... but does anyone know if it's been stated unequivocally since the cancellation of the full expressway project this week that the Black Cat to Caxton Gibbet dualling is definitely unaffected, and still going ahead? All I can find on-line is news derived from the same basic HE press release info about the whole expressway being cancelled and vague quotes from Grant Shapps mumbling about local schemes being unaffected. The latter suggests that the D2 Black Cat to Caxton section will still go ahead, but I can't find anything that says explicitly: "Despite the cancellation of the expressway, the A1 to Caxton dual carriageway is still happening". This thread mentions nothing, as if the expressway hadn't been cancelled this week, and the HE Facebook page, similarly, says nothing. Which might mean that it's business as usual, and everything re: the A428 dualling is still on track... but it might not, too!

Anyone know one way or t'other? Or let me re-phrase that: does anyone know one way or t'other and can say it publicly on here?

[owen b]

I can't find anything that says explicitly: "Despite the cancellation of the expressway, the A1 to Caxton dual carriageway is still happening".

I can't find that explicitly either, but I think that we can be very confident it will not be cancelled, because :
i) the HE press release explicitly refers to the cancellation of Oxford to Milton Keynes :
"Highways England had been developing potential options for a road link between Oxford and Milton Keynes. However, following close work with local partners since 2014, recent analysis shows that the benefits the road would deliver are outweighed by the costs associated with the project."
https://www.gov.uk/government/news/oxfo ... the-region
ii) The HE Black Cat to Caxton Gibbet page says nothing about any cancellation : https://highwaysengland.co.uk/our-work/ ... test-news/
iii) Black Cat to Caxton Gibbet is the last gap in a strategic link between Cambridge and Milton Keynes with a lot of development along its route and is a far advanced scheme and therefore logic says it would be very strange to cancel it at this late stage.

[KeithW]

The Development Consent Order application was made on 26 February 2021 so its rather unlikely it will now be cancelled.

[B1018 A120 M11]

Oooh, I hope this is right. I live near Cambridge and have family living on the B4031 as you head West out towards Deddington. You can virtually draw a straight line across the country that goes Cambridge-A428-A421-B4031, and for the last few years, the seriously terrible bit of this route has been between the Caxton Gibbet and the Black Cat. As well as leading in my personal case to close family, this route is also a great way to reach the Cotwolds (albeit that MK can be a bit of a pain if you hit it at bad times). As far as I'm concerned, the Black Cat flyover cannot come soon enough...!

I'm sorry to see the demise of the expressway, which could have had uses far beyond simply connecting the two university towns that somehow became part of its name (something like London Ultra-orbital might have been better... maybe one day...), but I did wonder if the NIMBYs in the safe Tory seats on the route would let that concept pass, and it seems it became too much of a political hot potato to survive. As people have already noted here, it seems like the NIMBYs will use any argument to prevent something new coming into their environments. If you live near the proposed expressway, then "car-orientated transport is evil and we should be looking at public transport". But if you live near the HS2 route, that's an overpriced white elephant too (I don't know what you do if you live at the intersection of HS2, East-West rail AND the now-ex-expressway — those people must be on permanent NIMBY overload).

I quite like the idea of East-West Rail — the only east-west rail route that survived the 60s via Peterborough is SO slow (as a Leicester University graduate who grew up in Essex and had other close family in Hereford, I personally remember its glacial, winding circumnavigation all the way from Colchester to Birmingham New Street only too well) and it will be great to have a more direct alternative... although it seems insane to (now) be considering building a diesel-only line in 2021. But around Cambridge, pressure groups (see the, to me, slightly batty Cambridge Approaches) have gone crackers at the idea of a new railway coming into Cambridge from the South and 'destroying their villages', and are trying to get it re-routed to enter Cambridge to the North of the city (despite the fact that such a route will, inevitably, equally inconvenience people living *there* — the classic NIMBY 'but as long as it's not near me, I don't care' approach). For me, the worst outcome is that the expressway and Black Cat overhaul is cancelled, and the NIMBYs do for East-West Rail. But I reckon we can't lose 'em all. I'd settle for Black Cat and a diesel East-West Rail (if we really must — clearly, electric would be better and more forward-looking), although it looks like the latter may have a fight on their hands with the likes of Cambridge Approaches...!


ASM Note : Some posts, including this one, have been copied or moved by the fairies to the East West Rail topic. Can we try to stay on topic in here please. Many thanks. Carry on...

[wrinkly]

I don't have any hard info either, but Black Cat to Caxton Gibbet is the last link in the upgrade of an existing trunk road. I don't think DfT/HE think of it as part of the cancelled project, which would have been a new trunk road where there was none before.

[ChrisH]

Skanska clinches £507m A428 dualling job

This is definitely still on. I can't figure out why the costs are now £507m - maybe this is only one part of the job? Or just one aspect of the work?

[SouthWest Philip]

Maybe time to drop 'rumour' from the thread title?

[Herned]

So the actual construction will cost ~£50m per mile including the Black Cat interchange. That seems entirely reasonable to me, and in line with other schemes and inflation from past schemes etc.

But where does the £1.4bn figure come from? I thought private finance type schemes weren't a thing these days? And land and planning won't come anywhere close to £900m - I assume this must be the cost over 30 years or something, but the HE scheme page doesn't go into any detail

[Jon Waters]

I thought Costain had the Contract and it was worth betweeen £800m- £1.2bn??

Jon

[jackal]

So the actual construction will cost ~£50m per mile including the Black Cat interchange. That seems entirely reasonable to me, and in line with other schemes and inflation from past schemes etc.

But where does the £1.4bn figure come from? I thought private finance type schemes weren't a thing these days? And land and planning won't come anywhere close to £900m - I assume this must be the cost over 30 years or something, but the HE scheme page doesn't go into any detail

There's no private finance but they still include operation and maintenance:

"The Scheme costs were provided by Highways England Commercial Services
Division (HECSD) in May 2019. The cost estimate was based on a Regional
Delivery Partnership (RDP) procurement route, with an expected outturn cost of
£812.5 million (2019 quarter 1 prices), including Portfolio risk.
The Operation and Maintenance costs were provided by HECSD in July 2020.
The net outturn cost for the Scheme was estimated to average £6.3 million a
year over 60 years in nominal terms, which includes inflation."

https://infrastructure.planninginspecto ... Scheme.pdf

[Herned]

There's no private finance but they still include operation and maintenance:

"The Scheme costs were provided by Highways England Commercial Services
Division (HECSD) in May 2019. The cost estimate was based on a Regional
Delivery Partnership (RDP) procurement route, with an expected outturn cost of
£812.5 million (2019 quarter 1 prices), including Portfolio risk.
The Operation and Maintenance costs were provided by HECSD in July 2020.
The net outturn cost for the Scheme was estimated to average £6.3 million a
year over 60 years in nominal terms, which includes inflation."

https://infrastructure.planninginspecto ... Scheme.pdf

Thank you... Which absolutely proves that you were right about how difficult it is to compare the costs between schemes. Is giving the cost over 60 years as the headline cost a new accounting methodology or a political wheeze to make the numbers as big as possible I wonder? Is the same costing used for other schemes?

[Chris5156]

The Clydach Gorge section of the A465 is costing less per km.

Likewise A465 sections 5 and 6 is £550m construction, £1.14m including financing. Frankly it's hopeless comparing across highways authorities due to such differences.

Let's also not pretend that the Clydach Gorge project has gone very well - I strongly suspect that the contractor is now losing money on the deal because it has suffered so many problems and gone far beyond its projected completion date. Work started on site between Gilwern and Brynmawr in December 2014 and was meant to be finished in 2017; that was already a year in the past when a new finish date of 2019 was announced. And today... the road is still not finished.

No contractor could bring a road in on budget, and still make a profit out of it, when they have been paying for materials, tools and a workforce, not to mention probable overrun penalties, for four years now. The price per kilometre of that cursed length of road is, at this stage, a fiction.

[jackal]

The project was accepted for examination by PINS today.

There's no private finance but they still include operation and maintenance:

"The Scheme costs were provided by Highways England Commercial Services
Division (HECSD) in May 2019. The cost estimate was based on a Regional
Delivery Partnership (RDP) procurement route, with an expected outturn cost of
£812.5 million (2019 quarter 1 prices), including Portfolio risk.
The Operation and Maintenance costs were provided by HECSD in July 2020.
The net outturn cost for the Scheme was estimated to average £6.3 million a
year over 60 years in nominal terms, which includes inflation."

https://infrastructure.planninginspecto ... Scheme.pdf

Thank you... Which absolutely proves that you were right about how difficult it is to compare the costs between schemes. Is giving the cost over 60 years as the headline cost a new accounting methodology or a political wheeze to make the numbers as big as possible I wonder? Is the same costing used for other schemes?

UK numbers are so high in part, as you say, for political reasons, to make investments look big. Though it's a bit of a double-edged sword as it might also make investments look like bad value for money. I don't really know if the 60 years' maintenance is a common thing.

I found this year by year breakdown of investment costs (not including operations and maintenance):

It's discounted to 2010 prices, so £812.5m has become £562m.

It's not too hard to see how the main works contract could be £500m as it probably does not cover preparation, supervision, land or all construction.

https://infrastructure.planninginspecto ... ndix_D.pdf

[roadtester]

One thing I noticed about the illustrations of the new stackabouted Black Cat junction is that it appears that the scheme will obliterate the current hotel, petrol station and other facilities just off the roundabout without replacement.

I'm slightly surprised if that is the case as this is a natural place for some facilities given the spacing of other stops/services along the route - perhaps a way could have been found to feed something off the new roundabout.

[thatapanydude]

One thing I noticed about the illustrations of the new stackabouted Black Cat junction is that it appears that the scheme will obliterate the current hotel, petrol station and other facilities just off the roundabout without replacement.

I'm slightly surprised if that is the case as this is a natural place for some facilities given the spacing of other stops/services along the route - perhaps a way could have been found to feed something off the new roundabout.

I would rather something wasn't placed on the mainlines as it would turn the risk of turning Black Cat into the mess at South Mimms (A1/M25) with the additional traffic services would bring. You could easily expand Caxton into a full-blown service station - with a larger Shell and hotel. On the A1 petrol stations are plentiful south of Black Cat likewise hotels in St Neots (though the one on Sandy roundabout closed a few months back). Maybe a petrol station could be built northbound between Black Cat and Buckden or restore the closed one just after the Little Paxton turn off nb.

[wrinkly]

The HA press release is here:

https://www.gov.uk/government/news/high ... -cambridge

[MotorwayPlannerM21]

HE just released a video about the scheme on their YouTube channel.