Next A14 Upgrade

[jackal]

I suspect there are many signalized roundabouts where the mainline is delayed by 30-60 seconds but this prevents potential delays of several minutes on the other roads.

Perhaps, but if the mainline has ~10 times as much traffic the signals may increase overall journey time (and especially for economically important HGVs). As the recent HE pinchpoint metastudy made clear, signalization moves delays around rather than removing them, with journey times increasing across most schemes.

[KeithW]

Perhaps, but if the mainline has ~10 times as much traffic the signals may increase overall journey time (and especially for economically important HGVs). As the recent HE pinchpoint metastudy made clear, signalization moves delays around rather than removing them, with journey times increasing across most schemes.

The drivers on the mainline are not the only ones entitled to use the roads, we peasants need to travel as well. It is little comfort for a driver on the A1101 trying to get across Fiveways that the HGV's will be able to deliver their loads of frozen chips to a supermarket 30 seconds faster.

[roadtester]

I hate driving on the chaotic Milton interchange and this is why *Link now fixed*

The writer is of the opinion that the junction is “confusing”, perhaps giving drivers the benefit of the doubt, that they appear unaware of the right exit to take until the late minute (whilst not condoning their behaviour).

However, I have a different take on it. Could it be that rather than smooth traffic flow, signalisation just increases the tendency for anti-social behaviour, or frustration in others??

The movement described in the article - A10 southbound to A14 westbound - is very confusing but it doesn't have anything to do with the signalisation. It's to do with the lane markings which are very messy in getting you between the third and fourth exits. Most people would intuitively stay in the right hand lane all the way around the roundabout until leaving at the fourth exit, but at the third exit all traffic for the fourth (A14) exit is required to take up position in the left hand lane. If you stay on the right until the fourth exit, you get caught out because the exit from the roundabout onto the 14 westbound has been hatched down to one lane, which is taken by traffic that has already positioned itself in the LH lane at the previous junction, rather than taking two lanes of traffic.

Difficult to describe but it's really odd and I've never come across anything quite like it anywhere else. I would guess that almost anyone who wasn't familiar with the junction would get it wrong.

[Berk]

Why would one lane be hatched out?? I don’t think hatching schemes like that are particularly helpful, they lead to exactly this sort of confusion.

[roadtester]

Why would one lane be hatched out?? I don’t think hatching schemes like that are particularly helpful, they lead to exactly this sort of confusion.

I'm not sure - there's already one lane of traffic funnelling in to the same exit via a sort of free-flow from the MIlton Road south of the roundabout, so I'm assuming that traffic from the roundabout itself needs to be kept down to one lane - otherwise, three lanes would have to be merged into one in a short distance on the slip-road itself, which I suspect might be even messier. Hopefully, this view should give some idea what I'm talking about:

https://www.google.com/maps/place/Milto ... !4d0.16144

[jackal]

Perhaps, but if the mainline has ~10 times as much traffic the signals may increase overall journey time (and especially for economically important HGVs). As the recent HE pinchpoint metastudy made clear, signalization moves delays around rather than removing them, with journey times increasing across most schemes.

The drivers on the mainline are not the only ones entitled to use the roads, we peasants need to travel as well. It is little comfort for a driver on the A1101 trying to get across Fiveways that the HGV's will be able to deliver their loads of frozen chips to a supermarket 30 seconds faster.

Being entitled to use the roads does not mean you're entitled to have them designed for your personal benefit.

[KeithW]

The movement described in the article - A10 southbound to A14 westbound - is very confusing but it doesn't have anything to do with the signalisation. It's to do with the lane markings which are very messy in getting you between the third and fourth exits. Most people would intuitively stay in the right hand lane all the way around the roundabout until leaving at the fourth exit, but at the third exit all traffic for the fourth (A14) exit is required to take up position in the left hand lane. If you stay on the right until the fourth exit, you get caught out because the exit from the roundabout onto the 14 westbound has been hatched down to one lane, which is taken by traffic that has already positioned itself in the LH lane at the previous junction, rather than taking two lanes of traffic.

Difficult to describe but it's really odd and I've never come across anything quite like it anywhere else. I would guess that almost anyone who wasn't familiar with the junction would get it wrong.

To walk you through as you come off the A10 and approach the Junction you see faded markings for the A14E in the left hand land and CITY/A14W in the RHL
https://www.google.co.uk/maps/@52.24012 ... 8192?hl=en

Having gone through the lights you see markings indicating that you should keep right for the A14W and take the third lane for the CITY
https://www.google.co.uk/maps/@52.23881 ... 6656?hl=en

Crossing the A14 the markings are
Left Hand lane - CITY
Right hand lane - CITY/A14W/A10
https://www.google.co.uk/maps/@52.23757 ... 8192?hl=en

All fine so far except for the wear.
Next exit you see
Lane 1 - CITY
Lane 2 - CITY/ A14W
Lane 3 - A10
Lane 4 - A10
https://www.google.co.uk/maps/@52.23699 ... 8192?hl=en

After this Lane 1 peels off as you approach the A14 so as you approach the next exit you should be in Lane 1 and normally Lane 2 would normally be OK too but this is marked A10 and the entry to the A14W is hatched off. In large part I suspect as the merge length is very short and there is another lane merging from the left.
https://www.google.co.uk/maps/@52.23720 ... 8192?hl=en

As I recall this was remarked a few years ago. Originally was pretty conventional with traffic staying in the RHL all the way around. As I recall the reason was that the volume of traffic coming out of Orchard Park and Cambridge heading for the A10N and A14E was effectively funnelled down into one lane and caused massive tailbacks along the Milton Road. The remarking allowed them to use 2 lanes for the A10 and allow the slip road from the A14W to flow straight on to the Milton Road.

The underlying issue is that the junction is simply inadequate. When it was built in the late 70's all there was to the south west was a farm and traffic levels were a fraction of what they now are.

[KeithW]

Perhaps, but if the mainline has ~10 times as much traffic the signals may increase overall journey time (and especially for economically important HGVs). As the recent HE pinchpoint metastudy made clear, signalization moves delays around rather than removing them, with journey times increasing across most schemes.

The drivers on the mainline are not the only ones entitled to use the roads, we peasants need to travel as well. It is little comfort for a driver on the A1101 trying to get across Fiveways that the HGV's will be able to deliver their loads of frozen chips to a supermarket 30 seconds faster.

Being entitled to use the roads does not mean you're entitled to have them designed for your personal benefit.

Its just as well I didnt ask for that then isnt it ? Had I designed it there would be a GSJ there.

Fiveways was designed when the A11 was an S2 road, it is now a much busier D2 and after the upgrade turning traffic was facing unreasonably long delays trying to use the unchanged unsignalled roundabout at peak. There was also a safety issue with a number of RTA's. If you want real delays a KSI accident will close the road for hours.
https://www.buryfreepress.co.uk/news/fi ... e-9055471/

Dont hold your breath waiting for an upgrade. It took 40 years for the A1 roundabouts between Blyth and Peterborough to be replaced with GSJ's and they still havent done that between Buckden and Baldock

[owen b]

All fine so far except for the wear.
Next exit you see
Lane 1 - CITY
Lane 2 - CITY/ A14W
Lane 3 - A10
Lane 4 - A10
https://www.google.co.uk/maps/@52.23699 ... 8192?hl=en

After this Lane 1 peels off as you approach the A14 so as you approach the next exit you should be in Lane 1 and normally Lane 2 would normally be OK too but this is marked A10 and the entry to the A14W is hatched off. In large part I suspect as the merge length is very short and there is another lane merging from the left.
https://www.google.co.uk/maps/@52.23720 ... 8192?hl=en

Quite frequently when I've been turning onto the A14 westbound from the A10 southbound I've had people cut me up by using the A10 lane and cutting across into my lane in front of me for the A14 onslip, sometimes across the hatching . It has happened far too frequently for it to be an accidental mistake every time.

[trickstat]

I suspect there are many signalized roundabouts where the mainline is delayed by 30-60 seconds but this prevents potential delays of several minutes on the other roads.

Perhaps, but if the mainline has ~10 times as much traffic the signals may increase overall journey time (and especially for economically important HGVs). As the recent HE pinchpoint metastudy made clear, signalization moves delays around rather than removing them, with journey times increasing across most schemes.

Of course there are probably quite a few places where the non-mainline is actually important for providing access to the wider network for HGVs from a large haulier or a factory.

[Berk]

Looking at the Google Views... it appears that the lane was hatched so that only there would be only one joining/lane gain on the A14 for the sake of it.

It’s something I’ve seen in quite a few places now. A 2-lane on-slip hatched down to one lane, for very little reason. Do on-slips have to be as wide as the main carriageway to keep two lanes?? Or is only one joining lane allowed??

[Berk]

I suspect there are many signalized roundabouts where the mainline is delayed by 30-60 seconds but this prevents potential delays of several minutes on the other roads.

Perhaps, but if the mainline has ~10 times as much traffic the signals may increase overall journey time (and especially for economically important HGVs). As the recent HE pinchpoint metastudy made clear, signalization moves delays around rather than removing them, with journey times increasing across most schemes.

Of course there are probably quite a few places where the non-mainline is actually important for providing access to the wider network for HGVs from a large haulier or a factory.

They’re hardly known for their lane discipline. Round here they often join lane 2 of the roundabout. Too bad if your slip is hatched.

[crb11]

All fine so far except for the wear.
Next exit you see
Lane 1 - CITY
Lane 2 - CITY/ A14W
Lane 3 - A10
Lane 4 - A10
https://www.google.co.uk/maps/@52.23699 ... 8192?hl=en

...

Quite frequently when I've been turning onto the A14 westbound from the A10 southbound I've had people cut me up by using the A10 lane and cutting across into my lane in front of me for the A14 onslip, sometimes across the hatching . It has happened far too frequently for it to be an accidental mistake every time.

I'm not so sure. I use this roundabout reasonably regularly and have to make a conscious effort to get into the correct lane if I'm heading down the A14W. The problem is that it's easy to miss that lane 2 splits, and a reasonable assumption for the roundabout would be that lanes 1 and 2 (which you can see going off that way) are just for the city, lane 3 is for the A14 and lane 4 is for the A10 and the relatively minor exit for Milton. This is how I think that part should be laid out in any case.

[owen b]

All fine so far except for the wear.
Next exit you see
Lane 1 - CITY
Lane 2 - CITY/ A14W
Lane 3 - A10
Lane 4 - A10
https://www.google.co.uk/maps/@52.23699 ... 8192?hl=en

...

Quite frequently when I've been turning onto the A14 westbound from the A10 southbound I've had people cut me up by using the A10 lane and cutting across into my lane in front of me for the A14 onslip, sometimes across the hatching . It has happened far too frequently for it to be an accidental mistake every time.

I'm not so sure. I use this roundabout reasonably regularly and have to make a conscious effort to get into the correct lane if I'm heading down the A14W. The problem is that it's easy to miss that lane 2 splits, and a reasonable assumption for the roundabout would be that lanes 1 and 2 (which you can see going off that way) are just for the city, lane 3 is for the A14 and lane 4 is for the A10 and the relatively minor exit for Milton. This is how I think that part should be laid out in any case.

Ok, fair enough, but in that case I'm sure that if you mistakenly ended up in the wrong lane you wouldn't cut up the person who was in the correct lane . You might go round the roundabout again. Or you might wait until all the traffic in the correct lane has cleared and then indicate and turn into the correct lane. What you wouldn't do is cut across the vehicle in the correct lane forcing it to brake or swerve. No doubt sometimes it is an honest mistake, after all it is not the most intuitive layout. But I suspect a lot of the time it is deliberate use of the incorrect lane in order to get to the A14 westbound more quickly, knowing full well that it will balk the vehicles in the correct lane.

[Berk]

Do you not think this is another example of why hatching should be avoided?? So far we’ve only covered incidents due to potential confusion, or discourtesy. It might one day lead to fatal consequences...

But at the end of the day, I cannot see why a functioning two-lane slip has to be hatched down to a single lane. It has the same effect as coning a lane off on the mainline, and everyone having to squeeze in line.

Are there new protocols regarding slips that we're not aware of??

[Bryn666]

Having two lanes deposit into a merge length causes numerous issues. If a merge needs two lanes then it gets a tiger tail entry these days and have done since the late 1980s.

[KeithW]

Do you not think this is another example of why hatching should be avoided?? So far we’ve only covered incidents due to potential confusion, or discourtesy. It might one day lead to fatal consequences...

But at the end of the day, I cannot see why a functioning two-lane slip has to be hatched down to a single lane. It has the same effect as coning a lane off on the mainline, and everyone having to squeeze in line.

Are there new protocols regarding slips that we're not aware of??

In this case no. The merge length would be unreasonably short. There are only 2 lanes at the exit for the simple reason that this is the way the roundabout junction was built in the late 1970's. If you look at the aerial view you can see where they have tweaked the roundabout by putting a bulge to the NE to squeeze in 3 lanes at that exit where there is really only room for 2,

https://www.google.co.uk/maps/place/Mil ... 6144?hl=en

As I have already said the bottom line is that this is a junction built in the late 1970s when Cambridge was still a sleepy university town and all that was at the junction was a quiet S2 road into Cambridge and Trinity Farm. There are now major industrial/research centres along with massive new housing developments in Milton and north along the A10 in Ely and Littleport as well as Newmarket to the east and Cambourne to the west. In our Cambridge Office most of the workforce was commuting in from locations from Bury St Edmunds, Bedford, Littleport, Royston and St Neots. The average commute was around 20 miles each way and the only option for most of us was by car to the nearest Park and Ride site.

The junction is simply loaded beyond its capacity with much more turning traffic than was considered to be possible let alone likely. Unfortunately I doubt anything substantive will happen until the implications of the Oxford Cambridge Expressway are clear and even then I have a hard time seeing what can be done as the southern half of the junction is so overdeveloped there is hardly room to swing a cat.

It may be possible to build a more efficient junction to the north such as a partially unrolled cloverleaf or some variation such as the A19/A66 junction on Teesside which copes very well with high levels of turning traffic. With a likely increase in traffic along both the A10 and A14 corridors ultimately someone is going to have to bite the bullet.

[camflyer]

The next significant upgrades will very likely be in Suffolk. I'm not aware of any comparable campaign elsewhere on the route.

https://www.suffolkchamber.co.uk/repres ... n-suffolk/

Surely the A14/A142 junction must be near the top of any improvement priority list. At the bare minimum it needs traffic lights at peak times. Ideally it needs a total rebuild.

[roadtester]

The next significant upgrades will very likely be in Suffolk. I'm not aware of any comparable campaign elsewhere on the route.

https://www.suffolkchamber.co.uk/repres ... n-suffolk/

Surely the A14/A142 junction must be near the top of any improvement priority list. At the bare minimum it needs traffic lights at peak times. Ideally it needs a total rebuild.

As a local, and a regular user, I'll vote for that one as well. It's just another example in the area of what twenty years ago was fairly decent, even over-dimensioned infrastructure, being overwhelmed by the economic/population growth since.

[dcrc2]

I don't remember if it's been posted here before, but a few years ago there was a report with some initial concept of what a future upgrade of J33 might look like, which was published in the Milton village newsletter. I didn't think to keep an original copy but it was basically this (existing slips to be removed are shown in black):

I'm not completely convinced that the existing bridges have enough span to allow for the extra offslip. But assuming this was actually checked when they came up with this, it doesn't seem like a bad idea. It would remove the set of lights at the top of the current EB offslip, which I would say is the main constraint on capacity in the evening peak.