A14 Cambridge to Huntingdon "news"

[ManomayLR]

As I said in the last post (edit after the post I'm quoting), there should be a sign on every gantry reminding of speed cameras - like here on the M1.

Ah I see - it's late and I drove back for 7 hours today, so I think I'm getting our wires crossed a bit... No speed camera reminder signs other than the ones that have been there for a few years on the northern bypass for the old SPECS average speed system. I would have hoped they would have been installed with the variable speed limit ahead signs, or planned to be installed very soon. Speed camera warning signs aren't required for enforcement generally on 'dumb' roads. Whether VSL changes that, I'm not sure.

Given all the evidence, I'm pretty sure that the HADECS aren't live to enforce anything other than maybe NSL. But I still didn't chance it and passed through them all within tolerance!

I wonder whether the smart motorway 'action plan' will apply to England's first smart A-road - will we be seeing stopped vehicle detection here soon? If not someone, somewhere, will make a racket about it.

[M11(A14(M))]

The very few VSL signs I saw were blue, but I did the whole length that evening and there were only 2 I could see

[Micro The Maniac]

As far as older roads to expressway standards are concerned, just adding the blue "autovia" signs as expressway signs would be enough in the first instance. Other signs can be changed from green to blue later.

Except having to build NMU paths for the whole length of the road.

Which shows the stupidity of not designating it a Motorway (sorry, Special Road) in the first place. The vast majority of this route is new-build and as such, there is no existing public right of way. Arguing that we can't now change (the brand new road) to motorway because we'd have to build in additional NMU provision is ridiculous. The old A14 is the NMU/LAR provision.

[KeithW]

I wonder whether the smart motorway 'action plan' will apply to England's first smart A-road - will we be seeing stopped vehicle detection here soon? If not someone, somewhere, will make a racket about it.

Possibly not given that the rest of the A14 has neither hard shoulders nor stopped vehicle detection, all we have on the A19 is the human eyeball mk 1.

[KeithW]

Which shows the stupidity of not designating it a Motorway (sorry, Special Road) in the first place. The vast majority of this route is new-build and as such, there is no existing public right of way. Arguing that we can't now change (the brand new road) to motorway because we'd have to build in additional NMU provision is ridiculous. The old A14 is the NMU/LAR provision.

Well the problem with that theory is the new road has good provision for NMU traffic and will have TRO's to restrict NMU traffic once the A1307 and new NMU routes are fully open.

The new A14 helps to improve safety by
separating strategic road traffic from local
traffic, including pedestrians and slow-moving
vehicles (cyclists, horse riders, agricultural
vehicles, mopeds and horse drawn vehicles).
The road also includes the latest safety features,
such as:
� incident management equipment including
electronic messaging signs and CCTV
� emergency refuge areas for those with
urgent vehicle problems
� variable speed limits to steady the flow of
traffic and reduce ‘stop-start’ traffic jams
� red X signs to manage traffic during vehicle
incidents and roadworks
Highways England produces Post Opening
Project Evaluation reports following the opening
of a road scheme. These are published one
year and five years after the scheme opens
and will examine how the scheme is meeting
all of our objectives, including our objective to
improve safety

[Micro The Maniac]

Which shows the stupidity of not designating it a Motorway (sorry, Special Road) in the first place. The vast majority of this route is new-build and as such, there is no existing public right of way. Arguing that we can't now change (the brand new road) to motorway because we'd have to build in additional NMU provision is ridiculous. The old A14 is the NMU/LAR provision.

Well the problem with that theory is the new road has good provision for NMU traffic and will have TRO's to restrict NMU traffic once the A1307 and new NMU routes are fully open.

That makes sense, given that it was designed to meet the Expressway/Motorway requirements...
... so even less of an excuse for not designating it a Motorway (sorry, Special Road)

[B1018 A120 M11]

OK, I dimly remember some discussion on this topic, I think, probably in this very thread, but I can't find it now (it's probably in the 200-odd pages somewhere...!). So excuse me if you've read about this already...!

I live a few miles from the Girton interchange, and often seem to end up making the journey A14 westbound (ie. north of Cambridge, former A45 northern Cambridge bypass) to M11 southbound. I had noticed that after all the recent rebuilding, the lane split at Girton was changed so that southbound M11 traffic (usually the way I'm going) peels off the A14 Westbound well in advance of Girton, and then, as far as I could see, A14 northbound traffic (ie towards the Midlands) gets the right-hand lane of the A14's remaining two lanes at this point, passing via the new slip road bridge and loop, and A428 westbound traffic (ie. towards Caxton Gibbet) takes the left-hand lane. I may have that wrong, as I'm usually turning off onto the M11 at this point and haven't taken too much notice of what the lanes on the A14 are doing past the point where I turn off (I've only driven the new A14 westbound to A14 north-west bound loop at Girton twice since it opened, once when most of it was still coned off and bits were being finished... and I can't remember exactly how the lanes are allocated).

Somewhere in the back of my mind, I thought it seemed a bit odd that A428 westbound traffic was effectively being reduced to one lane to pass Girton, particularly as I know that (a) the A428 continues to the Caxton Gibbet as D2 and (b) the A428 past Girton was D2 throughout before the rebuild. And as I said at the top here, I seem to remember some comment on here to that effect. But I rationalised this as follows: the A14 westbound has to split at Girton into the A428 westbound (to Caxton Gibbet) and the A14 northbound (to Huntingdon). You've got two lanes of road here in total, so it's fair that both routes get a lane each at the junction.

However, the other day, I drove some movements at Girton that I'd not travelled since the rebuild last year, and I realised how lopsided the new junction is. Firstly, of course, if the A428 still continues westbound past Madingley as D2 (which I know it does, as I have been over the bridges at the east-facing junction at Madingley Mulch plenty of times recently, from which you can see the D2 A428 passing unaltered underneath), then there must be a lane gain to 'put back' the second lane lost at Girton when the A14 heads up to Huntingdon. So when heading west from A14 north of Cambridge to A428 at Madingley, your route now goes D2-D1-D2 as you pass Girton.

The oddness still isn't particularly obvious when travelling in that direction. But the other day, I travelled on the A428 *eastbound* through Girton from Caxton for the first time since the rebuild — and that way round, it seems *very* weird. Perfectly good D2 A428 approaches Girton eastbound as it used to, then suddenly the right-hand lane vanishes and is hatched out for half a mile or so, reducing the D2 to D1. Then the A14 and M11 join and two lanes are restored, bringing the road up to its new widened D3 spec for the eastbound journey to Milton.

Moreover, I also travelled the A14 southeast from Bar Hill onto the A14 north of Cambridge at Girton recently for the first time since the works... and that stays D2 throughout, as far as I could see. So why do the A14 northbound, A428 westbound, and (most bafflingly of all) the A428 eastbound only have one lane to play with at Girton, to the point of creating a new pinchpoint for the eastbound A428 and hatching out a whole lane to bring the road down to D1 there? You pass all this in the blink of an eye, so I'm not sure, but I could swear the eastbound A428 *formation* remains wide enough for two lanes... but they've artificially narrowed it to one with the hatching.

I don't get it. Does anyone else, and if so... can you explain it to me?

[thatapanydude]

I've now travelled the new road.


On the other hand, driving along it is quite different from driving along a typical rural motorway; it feels more like an urban motorway (with a reduced speed limit, even though it's a 70mph road) than anything else. Even though I visited it at an uncongested time, few drivers were making much of an effort to do 70mph, and it feels like the junction spacing is very tight (especially with respect to junctions 24B/24A when going westbound). In fact, the road felt "faster" either side of the new section, than on the new section itself. The roads signed at the junctions are also generally very minor (with junction 24B connecting only to unclassified roads!), which also helped to make it feel less like it should be a motorway.

I fully agree, to be honest its closer to a standard of a primary HQDC not of a motorway. This is what the M53 at Birkenhead would look like if ALR'd (the D2 section). If the A14 was to become a motorway it would be one poorer motorways in terms of on-road quality - yes the tech is good but mixing the A1 and A14 together at Brampton isn't. Take the refuge areas on my point of quality, why couldn't they be built to this size? In fact the upcoming build of the A421 from black cat to caxton will have refuge areas akin to these.

Take the new section of A1 at Brampton. To the north its a full-spec motorway and to the south its an inadequate 70s at-grade DC, what in your view does it resemble closer too? In my opinion (again probably out on a limb) it feels more like at HQDC rather than motorway so I would prefer it kept that way.

On the subject of lane breakdown technology - let's first get it done on all D4/5 ALR sections of motorways first before we start moving to primary routes.

[thatapanydude]

OK, I dimly remember some discussion on this topic, I think, probably in this very thread, but I can't find it now (it's probably in the 200-odd pages somewhere...!). So excuse me if you've read about this already...!

I live a few miles from the Girton interchange, and often seem to end up making the journey A14 westbound (ie. north of Cambridge, former A45 northern Cambridge bypass) to M11 southbound. I had noticed that after all the recent rebuilding, the lane split at Girton was changed so that southbound M11 traffic (usually the way I'm going) peels off the A14 Westbound well in advance of Girton, and then, as far as I could see, A14 northbound traffic (ie towards the Midlands) gets the right-hand lane of the A14's remaining two lanes at this point, passing via the new slip road bridge and loop, and A428 westbound traffic (ie. towards Caxton Gibbet) takes the left-hand lane. I may have that wrong, as I'm usually turning off onto the M11 at this point and haven't taken too much notice of what the lanes on the A14 are doing past the point where I turn off (I've only driven the new A14 westbound to A14 north-west bound loop at Girton twice since it opened, once when most of it was still coned off and bits were being finished... and I can't remember exactly how the lanes are allocated).

Somewhere in the back of my mind, I thought it seemed a bit odd that A428 westbound traffic was effectively being reduced to one lane to pass Girton, particularly as I know that (a) the A428 continues to the Caxton Gibbet as D2 and (b) the A428 past Girton was D2 throughout before the rebuild. And as I said at the top here, I seem to remember some comment on here to that effect. But I rationalised this as follows: the A14 westbound has to split at Girton into the A428 westbound (to Caxton Gibbet) and the A14 northbound (to Huntingdon). You've got two lanes of road here in total, so it's fair that both routes get a lane each at the junction.

However, the other day, I drove some movements at Girton that I'd not travelled since the rebuild last year, and I realised how lopsided the new junction is. Firstly, of course, if the A428 still continues westbound past Madingley as D2 (which I know it does, as I have been over the bridges at the east-facing junction at Madingley Mulch plenty of times recently, from which you can see the D2 A428 passing unaltered underneath), then there must be a lane gain to 'put back' the second lane lost at Girton when the A14 heads up to Huntingdon. So when heading west from A14 north of Cambridge to A428 at Madingley, your route now goes D2-D1-D2 as you pass Girton.

The oddness still isn't particularly obvious when travelling in that direction. But the other day, I travelled on the A428 *eastbound* through Girton from Caxton for the first time since the rebuild — and that way round, it seems *very* weird. Perfectly good D2 A428 approaches Girton eastbound as it used to, then suddenly the right-hand lane vanishes and is hatched out for half a mile or so, reducing the D2 to D1. Then the A14 and M11 join and two lanes are restored, bringing the road up to its new widened D3 spec for the eastbound journey to Milton.

Moreover, I also travelled the A14 southeast from Bar Hill onto the A14 north of Cambridge at Girton recently for the first time since the works... and that stays D2 throughout, as far as I could see. So why do the A14 northbound, A428 westbound, and (most bafflingly of all) the A428 eastbound only have one lane to play with at Girton, to the point of creating a new pinchpoint for the eastbound A428 and hatching out a whole lane to bring the road down to D1 there? You pass all this in the blink of an eye, so I'm not sure, but I could swear the eastbound A428 *formation* remains wide enough for two lanes... but they've artificially narrowed it to one with the hatching.

I don't get it. Does anyone else, and if so... can you explain it to me?

Madness me neither too !! My dad tells me at the moment it isn't too bad in the mornings but lots are working at home right now so to be expected. This should rightfully be D2 though with the M11 joining as prior to the scheme. For lots of people of the A428 including my dad he joins in now on lane 3 along with HGV's too and now has to make his way to lane 1 for the science park (milton) like many others too making the mixing of traffic between lanes high.

[Bryn666]

Traffic flow predictions presumably place more traffic using the A14 to A14 movements so therefore they get more lanes at the expense of others. It happens elsewhere.

[B1018 A120 M11]

There are a few other things that I don't understand about the A14 upgrade, which, although it was ostensibly a premium regional project, seems bafflingly penny-pinching in its approach to design in a couple of places. I can't believe the absurd sprawl of the new Swavesey junction complex, and feel sure that there must have been a better way to achieve a meeting of the roads there than the multiple roundabouts that festoon the final design, even if there are local roads, a services, a new LAR and the A1307 to bring together here. Paging Truvelo and his fantasy designs for an improvement, please! Or anyone else...?

As part of the seeming over-complexity at Swavesey, I think it's particularly nuts that Cambridge to St Ives traffic now has to perform a 300-degree turn around a tiny roundabout, and another 90-degree turn around another small roundabout to reach the A1307 northbound, where once there was a seamless dual carriageway. I moaned about this at the design phase — somewhere earlier on this very thread I think. Let's just say that my opinion of the junction's design hasn't been swayed by the reality now construction is complete. I seem to recall that there was a seamless carriageway-split junction here at an earlier phase of the A14 upgrade's design, but presumably it was binned as it meant building another bridge?

Annoyingly, the same is true at the other end of the new-build section near Huntingdon and the Brampton Hut... where any westbound traffic coming off the A1 southbound, out of Huntingdon, or out of the Western Fens via the A141 heading for the Midlands is now funnelled via a 270-degree turn around a traffic circle barely bigger than a mini-roundabout (at the A14 on-slip). Were they SO short of land here that a gently curving sliproad (like the A11/A14 junction near Newmarket, and very much minus the congestion-generating roundabout) was really out of the question?

I'm also surprised at the poor connectivity between St Ives and the new road. If, heading for St Ives from Cambridge, you miss the monstrosity of a junction at Swavesey, you can't get off the new road until Brampton (yeah, there's that junction at the A1198, but it's eastbound-facing only... the westbound-facing slip roads at the A1198 junction are solely for emergency access). And trying to get onto the new road from St Ives involves some serious dog-leg routes (or passing through the 'orrible junctions at Swavesey or the Brampton Hut) before you finally make it on.

Finally, to complete 'moaning old git corner', I was surprised by some of the undulations and curves, and consequent poor sightlines on the new A14 section over the Ouse. Although I thought the plan was to build the new road to motorway spec (even if it didn't acquire that status in the end), the Ouse crossing section and the parallel A14/A1 section and junctions south of Brampton don't feel very motorwayish to me... more like a cut-price A-road from the late 70s. It looks big and impressive from the air, sure... but seemed rather more rollercoasterish to drive than I had anticipated it would be. Maybe that's just me?

OK, rant over...!

[Hdeng16]

There are a few other things that I don't understand about the A14 upgrade, which, although it was ostensibly a premium regional project, seems bafflingly penny-pinching in its approach to design in a couple of places. I can't believe the absurd sprawl of the new Swavesey junction complex, and feel sure that there must have been a better way to achieve a meeting of the roads there than the multiple roundabouts that festoon the final design, even if there are local roads, a services, a new LAR and the A1307 to bring together here. Paging Truvelo and his fantasy designs for an improvement, please! Or anyone else...?

As part of the seeming over-complexity at Swavesey, I think it's particularly nuts that Cambridge to St Ives traffic now has to perform a 300-degree turn around a tiny roundabout, and another 90-degree turn around another small roundabout to reach the A1307 northbound, where once there was a seamless dual carriageway. I moaned about this at the design phase — somewhere earlier on this very thread I think. Let's just say that my opinion of the junction's design hasn't been swayed by the reality now construction is complete. I seem to recall that there was a seamless carriageway-split junction here at an earlier phase of the A14 upgrade's design, but presumably it was binned as it meant building another bridge?

Annoyingly, the same is true at the other end of the new-build section near Huntingdon and the Brampton Hut... where any westbound traffic coming off the A1 southbound, out of Huntingdon, or out of the Western Fens via the A141 heading for the Midlands is now funnelled via a 270-degree turn around a traffic circle barely bigger than a mini-roundabout (at the A14 on-slip). Were they SO short of land here that a gently curving sliproad (like the A11/A14 junction near Newmarket, and very much minus the congestion-generating roundabout) was really out of the question?

I'm also surprised at the poor connectivity between St Ives and the new road. If, heading for St Ives from Cambridge, you miss the monstrosity of a junction at Swavesey, you can't get off the new road until Brampton (yeah, there's that junction at the A1198, but it's eastbound-facing only... the westbound-facing slip roads at the A1198 junction are solely for emergency access). And trying to get onto the new road from St Ives involves some serious dog-leg routes (or passing through the 'orrible junctions at Swavesey or the Brampton Hut) before you finally make it on.

Finally, to complete 'moaning old git corner', I was surprised by some of the undulations and curves, and consequent poor sightlines on the new A14 section over the Ouse. Although I thought the plan was to build the new road to motorway spec (even if it didn't acquire that status in the end), the Ouse crossing section and the parallel A14/A1 section and junctions south of Brampton don't feel very motorwayish to me... more like a cut-price A-road from the late 70s. It looks big and impressive from the air, sure... but seemed rather more rollercoasterish to drive than I had anticipated it would be. Maybe that's just me?

OK, rant over...!

St Ives is just a town. The old A14 was probably only just kept as a dual carriageway, and I very much doubt would be built as such from scratch. It's not ideal, but it's not a major problem no matter how many times you mention the turn degrees or roundabout sizes. You've got it a lot better than most and while the junction design is a little OTT I'm personally more bothered by the cycle provisions that just stop at this junction, rather than continue up the A1307 ex A14.

Not saying you're wrong... just don't think it's a massive problem.

[c2R]

Also... the A14/A1 parallel running section and junctions, while being a bit on the tight side are much, much better than the massive loop that was previously proposed!

[ManomayLR]

Also... the A14/A1 parallel running section and junctions, while being a bit on the tight side are much, much better than the massive loop that was previously proposed!

Why can’t they just build another 4-level stack?

[Al__S]

the Swavesey junction is an utter nonsense of bad layout. If I was trying to do better, the wish list would include:

Direct freeflow links A14 to A1307 westbound and A1307 to A14 eastbound

Less roundabouts, and they would be in a straighter line

I'd put the freeflow links to the west of the junction.

I'd possibly make the main interchange similar to the Bar Hill junction, with access to the Services from a roundabout to the south. However even at the Bar Hill junction I'd have done things a bit differently, with the A1307 going under the cycle bridge (as it does at Swavesey! there's space between the pier and abutment but the underpass of the B1050 would be longer/redesigned) with the NMU path going under the B1050 (at Swavesey, this would be Buckingway Road) separately. Access to the business park would be from a roundabout roughly in the same place (relatively) as the new B1050 Northstowe roundabout.

Further out I'd have reduced the A1307 from Swavesey to Huntingdon to a single carriageway with NMU path throughout, retaining (and indeed upgrading and adding) grade separated junctions with farm/driveway access by parallel local access appropriate to the property/ nearby crossing roads.

[KeithW]

OK, I dimly remember some discussion on this topic, I think, probably in this very thread, but I can't find it now (it's probably in the 200-odd pages

Moreover, I also travelled the A14 southeast from Bar Hill onto the A14 north of Cambridge at Girton recently for the first time since the works... and that stays D2 throughout, as far as I could see. So why do the A14 northbound, A428 westbound, and (most bafflingly of all) the A428 eastbound only have one lane to play with at Girton, to the point of creating a new pinchpoint for the eastbound A428 and hatching out a whole lane to bring the road down to D1 there? You pass all this in the blink of an eye, so I'm not sure, but I could swear the eastbound A428 *formation* remains wide enough for two lanes... but they've artificially narrowed it to one with the hatching.

I don't get it. Does anyone else, and if so... can you explain it to me?

Ok lets review what it was like in 2006. If you were headed westbound towards Girton along the Cambridge Northern bypass the road was D2 with the left signed lane for the M11 and A14 turns and right hand lane for the A428. There was one off slip for both the M11 and A14 which then divided. The left hand lane was always congested as the A14/M11 was the major traffic flow. This would also cause congestion on lane 2 as people waited until the last moment to merge. As the A428 was my route home this was a major pain. Heading eastbound along the A428 while there were 2 lanes only Lane 2 was usable as the A14 and M11 traffic effectively blocked lane 1 and of course the A14 at the time was only D2

So what they did intitally was westbound to add an extra lane at Girton Eastbound on the A14 this helped.

Westbound A14
before
https://www.google.co.uk/maps/@52.23200 ... 312!8i6656

after
https://www.google.co.uk/maps/@52.23247 ... 312!8i6656

The result however was that westbound traffic on the A14/A428 still queued along the approach as access to the A14 was just one lane up the spiral. The reality was that in practise if you were using the A428 you still got over to the outside for the A428, it was just that it was now lane 3. However that lane now flowed freely.
The traffic flow along that section of the A428 is under 20k.
https://www.google.co.uk/maps/@52.23176 ... 312!8i6656

Girton is frankly a bodge of the first order, a tiny half cloverleaf for the A14 North and M11 south worked sort of OK when the A604 (A14) was just a link to Huntingdon, Alconbury and Kettering but once the A14 opened all the way to Catthorpe and the A1(M) became 4 lanes at Alconbury it was simply overwhelmed which was made worse by the dualling of the A428 to Caxton Gibbet.

In an ideal world they would have completely rebuilt Girton as a freeflow GSJ with all movements as was done with the A19/A66 junction on Teesside.
https://www.google.co.uk/maps/@54.56268 ... a=!3m1!1e3

However in the real world this was not possible without completely disrupting the traffic flows around Cambridge which would have been unacceptable. It could be done on Teesside as both the A19 and A66 were new build.

At Girton the traffic flow is changed completely, the new A14 will take both the traffic for the A1(M) and A4 the new bypass so with current traffic levels the single lane for the A428 should cope. Of course once the A428 is dualled to the Black Cat all bets are off, the single lane at Girton will I suspect be the least of the problems, I can forsee that the rest of the Cambridge Northern Bypass will become overloaded especially when the M11 is made into a Smart Motorway with all lane running. Sooner or later the problem that is Girton will have to be faced, makes me glad I am now retired and its not my problem.

To be fair to Highways England their brief was not to solve all the traffic problems around Cambridge but to provide more capacity on the A14 and separate local and strategic traffic. I think they have made good job of that. I suspect the idea was to handle the wider problems in the context of the mooted Oxford-Cambridge Expressway but that scheme to be dying on the vine.

[c2R]

Also... the A14/A1 parallel running section and junctions, while being a bit on the tight side are much, much better than the massive loop that was previously proposed!

Why can’t they just build another 4-level stack?

Because the roads don't cross at anywhere near right angles - so having the parallel carriageways a la ferrybridge is a better solution. However, the road's curves are tighter than at Ferrybridge - presumably because there was less money available as part of the scheme

[KeithW]

the Swavesey junction is an utter nonsense of bad layout. If I was trying to do better, the wish list would include:

Direct freeflow links A14 to A1307 westbound and A1307 to A14 eastbound

Less roundabouts, and they would be in a straighter line

I'd put the freeflow links to the west of the junction.

I'd possibly make the main interchange similar to the Bar Hill junction, with access to the Services from a roundabout to the south. However even at the Bar Hill junction I'd have done things a bit differently, with the A1307 going under the cycle bridge (as it does at Swavesey! there's space between the pier and abutment but the underpass of the B1050 would be longer/redesigned) with the NMU path going under the B1050 (at Swavesey, this would be Buckingway Road) separately. Access to the business park would be from a roundabout roughly in the same place (relatively) as the new B1050 Northstowe roundabout.

Further out I'd have reduced the A1307 from Swavesey to Huntingdon to a single carriageway with NMU path throughout, retaining (and indeed upgrading and adding) grade separated junctions with farm/driveway access by parallel local access appropriate to the property/ nearby crossing roads.

The A1307 is a local access route NOT a strategic highway and at Huntingdon the only way to go further will be along the S2 Mill Common Link Road/ B1514. One of the main requirements for the new bypass was to separate local and strategic traffic so you absolutely do not want commuter traffic on the new A14 bypass. That is what the A1307 is for, the mixing of traffic and heavy weaving is why Girton to Bar Hill was such a mess. This is also why the east facing slips on the A14/A1198 junction are for emergency use only. The traffic planners definitely did not want commuter traffic from the new housing estates being built south of Godmanchester piling on to the new bypass on their way to Orchard Park and the Science Park.

I dont know of many D2 local access roads, when the A1 was upgraded to A1(M) around Wetherby the old road (now A168) was reduced to S2 for the same reason, its quite clear on Google Aerial View where old northbound carriageway was ploughed up.
https://www.google.co.uk/maps/place/Wet ... d-1.384816

[Hdeng16]

"Direct freeflow links A14 to A1307 westbound and A1307 to A14 eastbound"

This is absolute madness. They are simply not required.

[kiran_mk2]

OK, I dimly remember some discussion on this topic, I think, probably in this very thread, but I can't find it now (it's probably in the 200-odd pages somewhere...!). So excuse me if you've read about this already...!

I live a few miles from the Girton interchange, and often seem to end up making the journey A14 westbound (ie. north of Cambridge, former A45 northern Cambridge bypass) to M11 southbound. I had noticed that after all the recent rebuilding, the lane split at Girton was changed so that southbound M11 traffic (usually the way I'm going) peels off the A14 Westbound well in advance of Girton, and then, as far as I could see, A14 northbound traffic (ie towards the Midlands) gets the right-hand lane of the A14's remaining two lanes at this point, passing via the new slip road bridge and loop, and A428 westbound traffic (ie. towards Caxton Gibbet) takes the left-hand lane. I may have that wrong, as I'm usually turning off onto the M11 at this point and haven't taken too much notice of what the lanes on the A14 are doing past the point where I turn off (I've only driven the new A14 westbound to A14 north-west bound loop at Girton twice since it opened, once when most of it was still coned off and bits were being finished... and I can't remember exactly how the lanes are allocated).

Somewhere in the back of my mind, I thought it seemed a bit odd that A428 westbound traffic was effectively being reduced to one lane to pass Girton, particularly as I know that (a) the A428 continues to the Caxton Gibbet as D2 and (b) the A428 past Girton was D2 throughout before the rebuild. And as I said at the top here, I seem to remember some comment on here to that effect. But I rationalised this as follows: the A14 westbound has to split at Girton into the A428 westbound (to Caxton Gibbet) and the A14 northbound (to Huntingdon). You've got two lanes of road here in total, so it's fair that both routes get a lane each at the junction.

However, the other day, I drove some movements at Girton that I'd not travelled since the rebuild last year, and I realised how lopsided the new junction is. Firstly, of course, if the A428 still continues westbound past Madingley as D2 (which I know it does, as I have been over the bridges at the east-facing junction at Madingley Mulch plenty of times recently, from which you can see the D2 A428 passing unaltered underneath), then there must be a lane gain to 'put back' the second lane lost at Girton when the A14 heads up to Huntingdon. So when heading west from A14 north of Cambridge to A428 at Madingley, your route now goes D2-D1-D2 as you pass Girton.

The oddness still isn't particularly obvious when travelling in that direction. But the other day, I travelled on the A428 *eastbound* through Girton from Caxton for the first time since the rebuild — and that way round, it seems *very* weird. Perfectly good D2 A428 approaches Girton eastbound as it used to, then suddenly the right-hand lane vanishes and is hatched out for half a mile or so, reducing the D2 to D1. Then the A14 and M11 join and two lanes are restored, bringing the road up to its new widened D3 spec for the eastbound journey to Milton.

Moreover, I also travelled the A14 southeast from Bar Hill onto the A14 north of Cambridge at Girton recently for the first time since the works... and that stays D2 throughout, as far as I could see. So why do the A14 northbound, A428 westbound, and (most bafflingly of all) the A428 eastbound only have one lane to play with at Girton, to the point of creating a new pinchpoint for the eastbound A428 and hatching out a whole lane to bring the road down to D1 there? You pass all this in the blink of an eye, so I'm not sure, but I could swear the eastbound A428 *formation* remains wide enough for two lanes... but they've artificially narrowed it to one with the hatching.

I don't get it. Does anyone else, and if so... can you explain it to me?

I was trying to work out the Girton junction design as well. S As you point out dropping the eastbound A428 down to 1 lane seems a bit odd. I think the issue is the Huntingdon Road bridge: the span doesn't allow for 3 lanes eastbound which I think would be needed. The capacity is needed for the morning commute when you have large numbers of cars trying to get to (presumably) the Science Park coming from the West-side towns (St Neots, Cambourne etc) down the A428 and the Southern districts (Trumptington, Shelford, Harston etc) up the M11. Thus it makes sense for the M11-A14w/b link to be a lane gain rather than a merge but the Huntingdon Road bridge wouldn't allow this to happen. The A428 under the new A14 freeflow link is wide enough for two lanes - perhaps put in with a bit of forward thinking. Perhaps the lane drop could have occurred a bit later (i.e. 3 lanes under the M11 and dropping lane 3 before the Huntingdon Road bridge)?