Locals insist the flyover, planned since the 1970s, was supposed to get A47 traffic zooming over the roundabout without stopping. Road enthusiasts complain that there's no point bypassing a roundabout if you're going to install another roundabout and stop everybody anyway. Nobody, it seems, is a fan.
The best laid plans
To understand why everyone is so worked up, let's go back to the beginning.
Opened in 1975, the Kings Lynn Bypass is a short dual carriageway linking the junction of the A47 and A17 in the west to Hardwick Roundabout in the east. It lets through traffic avoid what was previously a single badly congested crossing of the River Great Ouse.
As originally built, the bypass ended at Hardwick, with the roundabout laid out so that it could eventually form a grade-separated junction with a flyover.
The intended layout was clear from the earthworks that were provided at the time the junction was built. The A47 dual carriageway would extend east towards Swaffham and Norwich, and a flyover would cross Hardwick Roundabout.
None of that happened. The A47 was never dualled east or west from King's Lynn, and the short bypass remained isolated, but Hardwick Roundabout became ever busier and more congested. Something had to be done.
In the early 2000s, roadbuilding was not fashionable and of little interest to the Government of the day. Further dualling of the A47 had been off the cards for years. Instead, the Highways Agency produced plans for a junction improvement that was considered fairly ambitious for its time: they were going to build a flyover.
Unexpectedly, they cleared away all the embankments that had been built up in the 1970s, built a viaduct spanning the whole junction, and installed a new roundabout at its eastern end. Curved sliproads linked the new roundabout to the old. Hardwick had its flyover, and with it, one of the UK's most distinctive and peculiar junction layouts. It opened in 2003.
The new junction is decidedly unconventional and doesn't appear to be a very smart way to add a flyover to a junction. Why speed through traffic across the roundabout only to stop it at another roundabout? It doesn't make sense.
Indeed, since 2003, the Hardwick Roundabout - and its funny little flyover - have come up in conversation dozens of times on the SABRE Forums, where road enthusiasts gather to discuss (and sometimes complain about) British and Irish roads. Every single time, the question has been why the second roundabout was added, and why the new flyover had to come packaged up with this weird junction design.
A bridge too far?
The Highways Agency's decision to build a lengthy viaduct right across the roundabout, held above the flat ground by a series of concrete piers, is a particularly interesting one given that the ground wasn't flat when they arrived to build their flyover.
Back in the early 1970s, when the King's Lynn Bypass was still under construction, the contract included work to provide embankments for flyovers to be provided later at both ends. The embankments at the junction with the A17 to the south-west of the town are still there, one on each side of the roundabout and a mound in the middle that would sit between two bridges.
The same was done at Hardwick, and since the A47 to the east was not on the right line to connect to the future flyover, the new embankment extended some way east of the junction too. You can see it being built in this aerial photo taken at the time.
For the next twenty years, the plan was to finish the junction and extend the dual carriageway. As recently as 1996, in fact, legal orders were published for a scheme to build the flyover exactly as originally planned, even though the dualling project had been dropped. This project was abandoned shortly afterwards too.
Between 1996 and 2003, then, the Highways Agency appear to have lost their minds. Instead of completing the junction, they cleared away the earthworks and built a totally different and inexplicably odd design. What on earth were they up to?
Method in the madness
That 1996 plan might just be key to understanding the whole project. With no prospect of the A47 being dualled east towards Swaffham, the huge new dual carriageway flyover and its sliproads would have stopped dead just east of Hardwick, the fast new road reverting to the old at a roundabout providing access to the houses on Constitution Hill. That's not a very good outcome for all that effort and expense.
If the A47 to the east was going to remain a single carriageway road with villages, houses and farm gates by the wayside, there was little point feeding a 70mph dual carriageway into it. The real problem at Hardwick was that the roundabout was overloaded, so when the project returned to the trunk road programme in the early 2000s, it was re-examined from scratch.
The congestion on the roundabout is not caused just by traffic wanting to stay on the A47, which the conventional flyover would serve. Large volumes are trying to get between the other four arms of the roundabout and the bypass. Could the flyover relieve that traffic too?
Well, yes, it could. The strange configuration of the junction means that traffic leaving the bypass is divided, joining the roundabout in two different places depending on where it's going. No journey off the bypass uses more than about a quarter turn of the junction now.
In the same way, traffic heading towards the bypass leaves the roundabout in two places, making at most a quarter turn of the junction. Where it passes around the smaller roundabout, it avoids any conflict with the traffic coming off the bypass.
In this way, the flyover doesn't just serve A47-A47 movements; it relieves the roundabout of large volumes of traffic travelling in every direction to and from the bypass. It is a kind of understated genius.
Today, there is a renewed push for funding to dual the A47 between King's Lynn and Swaffham. No problem: if that happens, a second bridge can still be built alongside the first, and the junction converted to the layout that was originally intended. The current design doesn't prevent that; it simply makes the maximum possible use of the flyover, taking advantage of the fact that the dual carriageway goes no further.
It may even be the case that, if a conventional layout is built, the complaints from locals and road enthusiasts alike that this strange layout makes no sense will be replaced with complaints that the roundabout is overloaded again - because a conventional flyover couldn't possibly provide such complete and complex relief to the roundabout as the present flyover does.
The only remaining question is why the flyover was built as a long viaduct, rather than making use of those embankments, which would have been perfectly good for the current layout and would have meant building two much smaller and cheaper bridge structures.
It's certainly one of the stranger parts of the junction works that were carried out in 2003, but unfortunately no answer to that question has ever been provided. Perhaps the Highways Agency needed the earth for use in another project, or perhaps they just thought a long viaduct would look nicer. Who knows?
While the junction layout might be rather clever, then, in that sense at least the Hardwick Flyover really is Imperfectly Odd.
This came out quick!
I remember this all being built when I was growing up! If I recall from the local press at the time, the earthworks / mound was removed to make it easier to build the second bridge later on if required - not sure why, but that was the reason given. If you look at the existing flyover it only has streetlights on one side so you can work out where the second flyover was envisaged to go!
The other mystery (to me anyway!) is at the other end of the King’s Lynn Bypass, where it meets the A17. The mound here seems to suggest the idea was to build a flyover to connect the A47 from the east to the A17 to the west. But most traffic turns off to stay on the A47 towards Peterborough and the A1(M). So what was the thought process here - was the A17 going to become more of a major east / west route here?
The A17 is a former trunk route, and is historically the main route between northern England and East Anglia. At the time it would have been the logical way to connect the bypass.
I think most freight traffic has now switched to the longer A1/A47 route (or A1/A14 for those heading to Suffolk) due to the generally unimproved nature of the A17.
Last time I went across Hardwick, the biggest problem wasn't particularly the roundabout - it was more that that the A 149 towards Hunstanton was jammed almost solid. The light phasing allowed a little traffic from King's Lynn to join the A 149, but traffic from the A47 and A10 couldn't get across the box junction.
Until now, I never knew the arrangement was built in mind for A47(E) to A10(S) to use the flyover and join the roundabout later. Reminds me a bit of Longbridge Island where A46(S) to M40(W) traffic is instructed to cross the motorway over the newer flyover and join the roundabout from the southern end.
I proposed this for Bad Junctions a few years ago (flying over a roundabout to land on a roundabout will never not be daft), but got shot down on the grounds listed here, that it eases a chunk of the strain on the roundabout by distributing the entries from one side to both.
I still disagree. I lived in Hunstanton (up the A149 from here, probably the most logjammed arm of this roundabout during the summer months) for many years, leaving in '98, and this short-sighted solution was not what was sold; it's tantamount to a big sign in the middle of the roundabout saying "we're not dualling the A47 so shut up about it". Any dualling will now involve building another bridge (when it should have been done properly in the first place), and presumably flattening the eastern roundabout (when it should have been done properly in the first place).
The meme at the time was of traffic getting here from the A47, going all the way round and going straight back home screaming.
There's a persistent rumour that the A10 is going to be rerouted to meet the A47 further east of here, to relieve the strain on West Winch (which is set for housing development). If that was extended to (say) the QE roundabout, or maybe Knight's Hill, or even (at a real stretch) Castle Rising, it could destress the roundabout by leaving it to mainly handle local traffic for South Lynn.
Poor design and one that could have been simplified even further with clover leaf style on the east side of the roundabout.so traffic flows dont cross on that east side. silly design it is as is. needed further work.
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- 1990s flyover scheme: The A47 Trunk Road (Hardwick Roundabout Flyover and Slip Roads) Order 1996.
- Images of Hardwick Roundabout and Flyover © 2020 Google.
- Plan of 1990s flyover scheme extracted from The A47 Trunk Road (Hardwick Roundabout Flyover and Slip Roads) Order 1996 and used under the terms of the Open Government Licence.