Where is it?
The point where a recently built and vitally important east-west link, the A14, meets a spur from the A1 allowing access between the A14 to the east and the A1 to the north.
What's wrong with it?
Quite aside from the fact that three arms of this four-way junction are numbered A14 (the fake one is the one to the north, which is a four mile spur to the A1 further north), this junction gets its priorities all wrong. The main flow of traffic is on the A14 between the east and west, meaning that most traffic has to negotiate the roundabout.
Coming westbound, there are huge gantry signs to alert motorists to the fact they have to turn off at this exit to stay on the same road. If you look closely at the aerial photo, you can see the problems this causes — the photo actually shows traffic backing up on the A14 to the east and the westbound off-slip.
Why is it wrong?
The A14 is a new road, but rather than being new build (aside from a few short bits) it's mostly cobbled together out of bits of other road. This section used to be the A604 (under the roundabout) which at the time took the main traffic flow. When the A14 came, it needed to turn off the A604 alignment and head west, but the junction wasn't altered.
What would be better?
It's hard to say, but there are lots of ideas floating around. The government's multi-modal study reccommends a whole new A14 alignment that avoids Huntingdon and this whole mess by a good few miles.
Right to reply
The major problem with this junction is when travelling from west to east. The green signs and the road markings give differing information about whether the A14 is straight over or right. And this is compounded by people going straight over from the right hand lane and turning right from the left hand lane. The number of near misses I see is extraordinary.
The Highways Agency have recently installed lights at this junction. I'm fortunate not to have to use this at peak times but it does seem to be mentioned less on travel reports now.
Have things improved? It strikes me that they have missed an obvious trick here. One of the main traffic movements here is actually one of the easiest to cater for. A free flow link from the northbound A14 (from M11) onto the westbound direction (towards M1/M6) would by-pass the roundabout with its lights, removing the frustrating and dangerous queues on the slip road.
I imagine the reason for not doing this (apart from cost) is that to access the nearby business park from the west you have to do a full circuit of the roundabout. You would then have to fight your way across such a free flow slip road if it were built. The access to this should never have been put so close to the roundabout. As for east/southbound traffic you will just have to wait to 2010? 2012? ...for something which should have been done in 1994.
As mentioned, there can't be a filter lane (or two) for all that westbound traffic due to the business park. However, I think a more pressing issue here is the backing up of traffic onto the eastern part of the westbound carriageway.
The only thing necessary to fix this would be to repaint the road so that both lanes turned off to join the roundabout, with a "slip road" diverging from the /right/ of those lanes to continue towards the A1(M). It would certainly be an unconventional layout, but it would be safer and less confusing for drivers, as it wouldn't feel like a TOTSO any more.
I suppose with the imminent final approval of the A14 Huntingdon to Cambridge bypass plans, we'll finally see an end to this ghastly junction, when construction is completed, as no doubt it will be downgraded and perhaps converted to a single level at-grade roundabout to serve the ever expanding Huntingdon. Not the grand method I was hoping, but hey, at least we'll be getting a new three lane A14 to the south and a widened A1 to the west!
This is indeed a very silly junction: my family sometimes use the A14 on the journey north from London and more than once we have failed to spot the turn-off-to-stay-on and ended up on the A1 northbound - on one occassion doing a little loop round the outskirts of Huntingdon to get back on track again. This is easily done especially in bad weather and when engaged in conversation with a passenger. My uncle got caught out by this junction the other day, but was at least able to enjoy the delights of Grantham services and the Nottingham Ring Road...