Oxford to Cambridge expressway

[rasingram2]

Hmmm ruddy 421/428. Why aren’t they one number already! (Yes I know they also go elsewhere but clearly this is the primary long distance route!).

I was looking at some old maps recently, and noticed that the A1-Bedford road used to be the A428. Was it changed when the new road was constructed from the M1 to the other side of Bedford, and then took over the eastern side?

[Chris5156]

Does anyone think we're missing a trick by not centreing the roundabout?? Just a few metres eastwards, roughly where the slips are on the diagram.

That would stop queues building up slightly, and you could include building a short bypass of the marina section, like I already mentioned.

By "centreing the roundabout" do you mean realigning the A1 to run further east? If so, I don't see what difference that would make to queues, it would be the same junction serving all the same traffic but in a slightly different location. It would also be a huge amount of extra expenditure and hassle for work that will probably turn out to be abortive if and when the A1 is realigned. Better to do the minimum to the present A1.

[Nader]

Hmmm ruddy 421/428. Why aren’t they one number already! (Yes I know they also go elsewhere but clearly this is the primary long distance route!).

I was looking at some old maps recently, and noticed that the A1-Bedford road used to be the A428. Was it changed when the new road was constructed from the M1 to the other side of Bedford, and then took over the eastern side?

I believe when the Bedford Southern Bypass was constructed and effectively 'joined' the A421 to the A428, the whole road from the M1 to the A1 was numbered A421. The A428 that still ran from Bedford out to the Eastern end of the bypass was imaginatively renumbered the A4280 (though there are still signs for A428 in Bedford)

[Owain]

Hmmm ruddy 421/428. Why aren’t they one number already! (Yes I know they also go elsewhere but clearly this is the primary long distance route!).

I was looking at some old maps recently, and noticed that the A1-Bedford road used to be the A428. Was it changed when the new road was constructed from the M1 to the other side of Bedford, and then took over the eastern side?

I believe when the Bedford Southern Bypass was constructed and effectively 'joined' the A421 to the A428, the whole road from the M1 to the A1 was numbered A421. The A428 that still ran from Bedford out to the Eastern end of the bypass was imaginatively renumbered the A4280 (though there are still signs for A428 in Bedford)

You are correct!

The A421 originally terminated on the A428, meaning that the road between the M1 and A1 used to change number at Bedford. However, when the route between the M1 and A1 was dualled fully it took the A421 number for consistency. Something similar happened when the M3 was completed; the A34 originally terminated where it merged with the A33, but the A34 number was extended to meet the new motorway. The A34 took priority over the A33 just as the A421 now takes priority over the A428, even though the A33 and A428 are the numbers that continue onwards to Southampton and Cambridge respectively.

And yet still nobody has sorted out the A417/A419 inconsistency!

[si404]

I believe when the Bedford Southern Bypass was constructed and effectively 'joined' the A421 to the A428, the whole road from the M1 to the A1 was numbered A421.

I thought it happened with the Great Barford bypass, however my 2000 AA and 2006 Michelin Atlases have it as A421, so it was clearly when the Bedford bypass opened.

The A428 that still ran from Bedford out to the Eastern end of the bypass was imaginatively renumbered the A4280 (though there are still signs for A428 in Bedford)

That didn't happen until the western bypass opened. The M1-Bedford and western bypass schemes lead to some weird renumberings in the area.

[skiddaw05]

The A421 originally terminated on the A428

But before then the A421 ended at Buckingham. The main route to Bedford used to be the A422, joining the A428 near Bromham.

[jackal]

The main Oxford-Cambridge scheme, which this thread used to be about, seems to include widening on the A421, and the A34 as far as the M4. (And you mean A421.)

Hmmm ruddy 421/428. Why aren’t they one number already! (Yes I know they also go elsewhere but clearly this is the primary long distance route!).

Discussion of them seems pretty central to OxCam as they are it!

Black Cat-Caxton Gibbet and the Oxford-Cambridge Expressway are two distinct schemes, at very different stages of development. Black Cat-CG had its own well-populated thread already (viewtopic.php?f=1&t=35879) but has now taken over the other scheme's thread. And yes, things are a little complicated by the fact that one scheme is effectively part of the other

[marconaf]

That thread is a bit old though? Although yes this repeats it. But as they say, repetiton is the mother of all learning

I suggest however that with a 3 level Jn and other improvements, offline A1 is dead. We may be in an era where roads get some more sensible attention (compared to the last few decades) but we aren’t back in the 70s in terms of thinking (good as it was a bit OTT).


In terms of schemes, the 421 & 428 are de facto the western ends of the OxCam scheme, as is B.Cat - C.Gibbet. A suspicious person would have said these, as were Bedford/A421 and C.Gibbet - Cambridge were simply chess pieces in a Govt plan to have built this route for a long time - only public as the MK-Oxfd requires breaking cover! Afterall, what chance would a HQDC from Oxfd-Camb have had if neither A421/428 existed already?

My issue is whether they will have the capacity once the longer route options are opened up by the central MK-Oxfd section.

Equally the A34 will need (online?) upgrading (D3) to the M4 at least. Is there any talk of that?

Still curious as to how the Oxford end will work, going North of it implies the M40-MK section ends near Bicester, S of it implies more Thame - with implications for routing E of M40 and proximity/connections to other towns.

[jackal]

^ Generally sensible. I would add that the A14 (esp. Cambridge northern bypass) is also a crucial part of the scheme. It's already rather congested with the A428 a basketcase contributing a trivial amount of its traffic. If the A428 becomes part of a major cross country expressway with traffic to match the bypass could get severely overloaded, and I wonder how much scope there is for further widening of it.

As for getting past Oxford, there is no progress, unless you count all options remaining open due to the selection of the central corridor (B).

[si404]

^ Generally sensible. I would add that the A14 (esp. Cambridge northern bypass) is also a crucial part of the scheme. It's already rather congested with the A428 a basketcase contributing a trivial amount of its traffic. If the A428 becomes part of a major cross country expressway with traffic to match the bypass could get severely overloaded, and I wonder how much scope there is for further widening of it.

Probably the best, though totally unlikely, scenario is to remove the long distance/freight traffic from the East Coast Ports from the Cambridge northern bypass by building a 'grand contournement nord' from Swavensey to Newmarket. You can even sell it by putting junctions serving various new developments in the area.

[KeithW]

^ Generally sensible. I would add that the A14 (esp. Cambridge northern bypass) is also a crucial part of the scheme. It's already rather congested with the A428 a basketcase contributing a trivial amount of its traffic. If the A428 becomes part of a major cross country expressway with traffic to match the bypass could get severely overloaded, and I wonder how much scope there is for further widening of it.

As for getting past Oxford, there is no progress, unless you count all options remaining open due to the selection of the central corridor (B).

The A428 is reasonably well used as far as Caxton Gibbet (30k +) and is still carrying around about 20k on the S2 section to Wyboston and the A1 so I think there is clear potential for growth there once upgraded. Traffic on the northern bypass tapers off pretty quickly once you get east of the Science Park (60k to 40k) but I think it would be prudent to increase the A14 to D3 from Girton to at least the A14/A11 merge. In the short term the choke point travelling to Oxford will remain the slog through the roundabout hell that is Milton Keynes. West of MK dualling the A421 as far as the A43 for the M40 should be relatively easy if a low cost solution was needed. Long term though a new route south of Bletchley is needed and the real problem will be getting from the M40 to Oxford. The A34 is simply not up to the job and has limited scope for improvement. When I was regularly doing the Oxford Cambridge run that was the real bugbear. Short of heading south and taking the M4/M25 there was no real alternative. I just dont see the B1 corridor as a being viable.

[KeithW]

In terms of schemes, the 421 & 428 are de facto the western ends of the OxCam scheme, as is B.Cat - C.Gibbet. A suspicious person would have said these, as were Bedford/A421 and C.Gibbet - Cambridge were simply chess pieces in a Govt plan to have built this route for a long time - only public as the MK-Oxfd requires breaking cover! Afterall, what chance would a HQDC from Oxfd-Camb have had if neither A421/428 existed already?

The A428 upgrade between Caxton Gibbet and Cambridge was needed anyway once the decision to green light the Cambourne new town development was given and as I recall a degree of developer funding was provided. The old road was heavily loaded and very congested at both the Cambridge and Caxton ends even without the new developments planned in Cambourne, Papworth, Godmanchester and St Neots. Similarly the old A428 route through Bedford was simply unsustainable as it was. The only realistic routes between M11/A1 and M1 were either the A14/A45 or the A603/A421 and the slog down the old Woburn road via Marston Moretaine was no fun at all. In fact the most common route chosen between our offices in Oxford and Cambridge was A603 - A1(M) - A414 - M25- M4 - A34

During the period that these routes were being built the governments in power had a quite different transport policies so long term government plans are unlikely at best and an oxymoron at worst.

[KeithW]

Black Cat-Caxton Gibbet and the Oxford-Cambridge Expressway are two distinct schemes, at very different stages of development. Black Cat-CG had its own well-populated thread already (viewtopic.php?f=1&t=35879) but has now taken over the other scheme's thread. And yes, things are a little complicated by the fact that one scheme is effectively part of the other

Black Cat-Caxton Gibbet was recognised as being needed when the A428 was dualled as far as Caxton Gibbet but stalled for years while decisions on the A1 upgrade and Black Cat were repeatedly delayed. It reached full Catch 22 level when each decision became dependent on the other. At least somebody has finally cut the knot.

[Robert Kilcoyne]

In the short term the choke point travelling to Oxford will remain the slog through the roundabout hell that is Milton Keynes. West of MK dualling the A421 as far as the A43 for the M40 should be relatively easy if a low cost solution was needed. Long term though a new route south of Bletchley is needed and the real problem will be getting from the M40 to Oxford. The A34 is simply not up to the job and has limited scope for improvement.

There would surely have to be significant improvements to Junctions 9 and 10 on the M40 if Oxford-Cambridge traffic had to use those junctions; both of those junctions cause frequent delays as it is. I am inclined to think that a more southerly route passing closer to Leighton Buzzard, Aylesbury and Thame may be the best long term solution as it will be virtually impossible to upgrade the A34 at Botley and North Hinksey.

[KeithW]

There would surely have to be significant improvements to Junctions 9 and 10 on the M40 if Oxford-Cambridge traffic had to use those junctions; both of those junctions cause frequent delays as it is. I am inclined to think that a more southerly route passing closer to Leighton Buzzard, Aylesbury and Thame may be the best long term solution as it will be virtually impossible to upgrade the A34 at Botley and North Hinksey.

Ideally Junction 9 should be rebuilt as freeflow but doing so without causing gridlock would be quite a trick. As for Junction 10 they spent years tinkering with it. Sounds like we may get Junction 8B next

[skiddaw05]

Something I've been wondering about this.
Once we get a high powered route between the two cities in whatever form it might take what happens beyond Oxford? The logical extension to the predominantly NE-SW alignment would be towards Swindon to join the M4. Which would need a significant upgrade to (or replacement of) the A420, otherwise this road could become completely swamped by the extra traffic.

[Truvelo]

I assume most of the traffic would use A34 and M4 to get to the west country. In which case freeflow links between the west and north at Chieveley will be needed. This should be cheaper than upgrading the A420.

[c2R]

I'm honestly not sure... The A420 runs through a corridor where additional capacity could be added; it's mainly rural other than at both ends and already is a former trunk route so there's a couple of improved sections. The A34 route is also 15 miles longer (more pollution as cars will drive wasted miles), and even at night Google is reckoning on it being 6 minutes longer.

The A34 itself between Oxford and the M4 is of a poor standard, and the M4 is congested at peak hours, so an A420 upgrade may add additional network resliance without adding substantially to the cost of the project (unless do-nothing is the option for the A34 here, which I doubt). Of course, it all depends on traffic pattern analysis and forecasting I suppose.

[roadtester]

Probably the best, though totally unlikely, scenario is to remove the long distance/freight traffic from the East Coast Ports from the Cambridge northern bypass by building a 'grand contournement nord' from Swavensey to Newmarket. You can even sell it by putting junctions serving various new developments in the area.

I was just thinking this the other day - although maybe not quite of that length.

I suppose it would have been best to do it all as part of a more ambitious version of the Cambridge/Huntingdon scheme, with an offline, rather than online upgrade at the eastern end avoiding the Girton interchange altogether and bypassing all or part of the Cambridge northern bypass section of the A14.

One objection would be that in planning terms, it would have the effect of effectively redefining the boundary of Cambridge to the north - the tendency in Ely, for example, has been to build out towards the bypass on the western side, which has effectively become the new boundary. I would say uncorking Cambridge development to the north would be a good thing, but a lot of locals might not agree.

[roadtester]

In terms of schemes, the 421 & 428 are de facto the western ends of the OxCam scheme, as is B.Cat - C.Gibbet. A suspicious person would have said these, as were Bedford/A421 and C.Gibbet - Cambridge were simply chess pieces in a Govt plan to have built this route for a long time - only public as the MK-Oxfd requires breaking cover! Afterall, what chance would a HQDC from Oxfd-Camb have had if neither A421/428 existed already?

The A428 upgrade between Caxton Gibbet and Cambridge was needed anyway once the decision to green light the Cambourne new town development was given and as I recall a degree of developer funding was provided. The old road was heavily loaded and very congested at both the Cambridge and Caxton ends even without the new developments planned in Cambourne, Papworth, Godmanchester and St Neots. Similarly the old A428 route through Bedford was simply unsustainable as it was. The only realistic routes between M11/A1 and M1 were either the A14/A45 or the A603/A421 and the slog down the old Woburn road via Marston Moretaine was no fun at all. In fact the most common route chosen between our offices in Oxford and Cambridge was A603 - A1(M) - A414 - M25- M4 - A34

During the period that these routes were being built the governments in power had a quite different transport policies so long term government plans are unlikely at best and an oxymoron at worst.

When I first moved to Cambs about twenty years ago, the A428 was scarcely usable as an east west route if you were in a hurry. The DC petered out not far west of Girton, so you were in for a long slog.

IIRC, the first upgrade was an isolated bit of dualling next to Cambourne that included the current GSJ followed by a gap of some years before the dualling was extended in both directions so that it was continuous between Caxton Gibbet and Girton.

It’s a terrific piece of road and it’s always a massive pain to hit the roundabout at CG going west. I almost always end up in McDonalds in order to fortify myself for the next stretch.