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Not what this shows but may be out of date. The slip road alignment typically starts at the point of the nosing, so the first 70m will be the nose where the alignment will shaddow the mainline one.
You would hope that if there was some optical illusion here, the approach to the roundabout wasn't clear the stage 3 road safety audit would have picked it up. Albeit at that stage you can't change the road layout, just chuck in extra road signs or road markings.
Bryn666 wrote: ↑Fri Jan 24, 2020 13:30
This is why DMRB is a nonsense compared to other European design standards; we encourage flat out speeds into a roundabout and then wonder why we have failed to stop collisions.
Much better to have a longer deceleration lane and curved slips to slow traffic to return to the 'ordinary' network. Beyond the wit of our ever decreasing skills, clearly...
How dare you criticise our lovely dmrb It's just been completley revamped you know, no doubt at great expense. Naff all content has changed but it has been re-drafted to comply with EU regulations. What a waste of money
Not what this shows but may be out of date. The slip road alignment typically starts at the point of the nosing, so the first 70m will be the nose where the alignment will shaddow the mainline one.
You would hope that if there was some optical illusion here, the approach to the roundabout wasn't clear the stage 3 road safety audit would have picked it up. Albeit at that stage you can't change the road layout, just chuck in extra road signs or road markings.
It is not clear which slip road it is that you are concerned about. This makes a difference as the plan shows the eastbound slips at the A1198 junction as being for emergency access and maintenance only. The other thing to bear in mind is the roundabouts may not be in their final configuration as there are still construction compounds in place. The aerial view on Bing Maps shows the actual state on the ground rather clearly.
The roundabouts are in final configuration. I can't work out how to post the pic but from lane 1 on the mainline you can see the roundabout chevrons, and on the slip Road the giant ADS also shows the roundabout. Perhaps people aren't expecting the roundabout to be so tight?
But if there are any issues these should be picked up by the RSA and we may get some additional paint and signs.
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There seems something odd about the forward visibility to the roundabout from the sliproad. Clearly there aren't currently chevrons on the roundabout because someone's driven through them...
darkcape wrote: ↑Sat Jan 25, 2020 17:24
The roundabouts are in final configuration. I can't work out how to post the pic but from lane 1 on the mainline you can see the roundabout chevrons, and on the slip Road the giant ADS also shows the roundabout. Perhaps people aren't expecting the roundabout to be so tight?
But if there are any issues these should be picked up by the RSA and we may get some additional paint and signs.
In which direction ?
The eastward facing slips are for emergency and maintenance use only, to a laymans eye the off slip from the eastbound A14 doesnt do anything to alarm me and the GSV image shows it as unfinished. https://www.google.co.uk/maps/@52.29341 ... authuser=0
Note that the A1198 is not a major road (it used to be when it was the A14) and with the Railway viaduct severed and the old A14 downgraded to the A1307 I really would not expect that much traffic on or off the new A14 except that heading south for the A428 at Caxton Gibbet and that is due for rebuilding anyway. The main traffic flows are going to be north/south on the A1198 to the residential developments at Godmanchester which to my untrained eye seems pretty decent.
c2R wrote: ↑Sat Jan 25, 2020 17:43
I wrote eastbound off-slip in the original post.
There seems something odd about the forward visibility to the roundabout from the sliproad. Clearly there aren't currently chevrons on the roundabout because someone's driven through them...
GSV showing top of eastbound A14 off slip in April 2019 - there were deinitely chevrons there. https://www.google.co.uk/maps/@52.29336 ... authuser=0
Could someone have driven through them - darned right they could, I watched a driver roll his truck into a 6ft deep pipe ditch once. That was a real panic, the ditch was full of live pipes some of which were carrying petrol and LPG.
The westbound off slip is for emergency and maintenance use only and because of the geometry and the entrance to the construction compound close by you would not see any chevrons from the main line of the A14. https://www.google.co.uk/maps/@52.29145 ... authuser=0
Ruler straight eastbound off slip plus low winter sun plus inattentive driver and it's quite easy to see why an overshoot may have happened.
This is not rocket science.
Why do we still build slip roads that allow you to carry on at 70+ into a junction?
The transition motorway speed to normal road speed should be enforced by curvature of slip roads so that a driver is made aware they are no longer on a fast dual carriageway.
You'd think Highways England would have worked that out by now.
Bryn Terminally cynical, unimpressed, and nearly Middle Age already. She said life was like a motorway; dull, grey, and long.
Berk wrote: ↑Fri Jan 24, 2020 14:22
That was very much noticeable when I was in Australia. Also, reducing mandatory speed limits on the approaches.
In Australia the approach to a roundabout, on an otherwise-high-speed dualled route, includes an S-bend just before the give-way line. This has been the standard for several years now. The bend is more severe than any I have seen in the UK. Vehicles have to slow down.
Berk wrote: ↑Fri Jan 24, 2020 14:22
That was very much noticeable when I was in Australia. Also, reducing mandatory speed limits on the approaches.
In Australia the approach to a roundabout, on an otherwise-high-speed dualled route, includes an S-bend just before the give-way line. This has been the standard for several years now. The bend is more severe than any I have seen in the UK. Vehicles have to slow down.
Apparently this would "confuse" our motorists so it's clearly better to have them overshoot the island totally...
Bryn Terminally cynical, unimpressed, and nearly Middle Age already. She said life was like a motorway; dull, grey, and long.
Bryn666 wrote: ↑Fri Jan 24, 2020 13:30
This is why DMRB is a nonsense compared to other European design standards; we encourage flat out speeds into a roundabout and then wonder why we have failed to stop collisions.
Much better to have a longer deceleration lane and curved slips to slow traffic to return to the 'ordinary' network. Beyond the wit of our ever decreasing skills, clearly...
How dare you criticise our lovely dmrb It's just been completley revamped you know, no doubt at great expense. Naff all content has changed but it has been re-drafted to comply with EU regulations. What a waste of money
DMRB rewrite was nothing to do with EU regs, although it did include some updates to references to BS ENs
Bryn666 wrote: ↑Sun Jan 26, 2020 11:31
Apparently this would "confuse" our motorists so it's clearly better to have them overshoot the island totally...
Overshooting the island sounds like Driving Without Due Car and Attention to me.
'Sorry officer I didnt notice the roundabout' would not cut it. There is street lighting on the roundabout so if anything it should be even clearer after dark,
Bryn666 wrote: ↑Sun Jan 26, 2020 11:31
Apparently this would "confuse" our motorists so it's clearly better to have them overshoot the island totally...
Overshooting the island sounds like Driving Without Due Car and Attention to me.
'Sorry officer I didnt notice the roundabout' would not cut it. There is street lighting on the roundabout so if anything it should be even clearer after dark,
Bryn666 wrote: ↑Sun Jan 26, 2020 11:31
Apparently this would "confuse" our motorists so it's clearly better to have them overshoot the island totally...
Overshooting the island sounds like Driving Without Due Car and Attention to me.
'Sorry officer I didnt notice the roundabout' would not cut it. There is street lighting on the roundabout so if anything it should be even clearer after dark,
The traffic on the M11 off slip has to give way to traffic on the unclassified Grantchester Road which meets it at an acute angle - lovely.
I know this M11 j12 southbound exit alignment well (especially at night after a Sunday evening A14 roadworks diversion).
A simple expedient - slashing down the overgrown bushes to the west of the M11 overbridge - would quickly lower the risk.
Note: lower the risk, not eliminate. I do not believe that any idiot could have designed this junction with a more-dangerous "over-the shoulder" view and sightline.
Mike Hindson-Evans. Never argue with a conspiracy theorist.
They will drag you down to their level and beat you with experience.
That’s interesting. The article claims only NMU’s are currently banned from the Southern Bypass, and a further is needed to exclude ‘motorcycles under 50cc’ and tractors and agricultural vehicles.
Has anyone seen any NO signs, or are they waiting to be put up?? Can the TRO’s be enforced without them?? And how far will the orders apply??
Berk wrote: ↑Sun Jan 26, 2020 14:51
That’s interesting. The article claims only NMU’s are currently banned from the Southern Bypass, and a further is needed to exclude ‘motorcycles under 50cc’ and tractors and agricultural vehicles.
Has anyone seen any NO signs, or are they waiting to be put up?? Can the TRO’s be enforced without them?? And how far will the orders apply??
That sounds right. I used the corridor on the 28th Dec as an NMU. It's not possible to access Cambridge via the A1307 heading SE, and heading NW, Bar Hill to Swavesey doesn't yet exist. I used it anyway, but it involved creativity with what tarmac was there, and a finale of riding the wrong way up the on slip for the SE carriageway, to get from one coned off area to another.
Not sure whether this should go here or in "numpty". Daughter was travelling on a late evening coach from London to Huntingon via Cambridge . The coach driver got rather lost on leaving Cambridge, going round roundabouts several times searching desperately for the right exit. He eventually went round the new bypass, up to Alconbury and back.
My daughter thinks he was confused by "road closed at Huntingdon " signs.
It's just been completley revamped you know, no doubt at great expense. Naff all content has changed but it has been re-drafted to comply with EU regulations. What a waste of money 
