Junction Confusion

Currently reading:
Junction Confusion

Joined
May 13, 2012
Messages
3,313
Points
844
Location
Quite south.
Here's an incredibly mundane topic that I feel the need to get off my chest
Once a week I commute to Chelmsford via the M25 and A12, junction 28 of the M25 going ACW in question baffles me and many other motorists every morning I travel that route.
Here's the particular area on streetview

And here's an exciting diagram I created to demonstrate how the lanes are labelled and where they propose the traffic go (blue arrows)
You'll have to click on this to make it bigger
M25:A12.jpg

The issue everyone seems to have is the two middle lanes on the exit slip road are labelled A12(E) but once you enter the roundabout which is traffic light controlled so all 4 lanes set off at the same time only 1 lane is designated A12(E). It usually results in some in the LH A12(E) lane taking the furthest left lane which is labelled to get back onto the M25 or the RH lane going into the A1023/M25(S) lane.
I usually take the LH lane A12(E) and end up in the middle lane where I am supposed to be but again you're stopped at another set of lights where cars are both in the A1023 lane and M25 lane wishing to be on the A12 so once the second set of lights change there's a lot of shuffling about and angry motorists trying to work out how to get back into the now 2 lanes provided for A12(E)!
Anyone care to chime in on this mess? :D
 
With any roundabout, lanes have to peel off at each junction. It should be possible for a lane to expand, but not contract.

From the slip road, lane 4 (always counting from the left) cannot go anywhere but into lane 3 across the roundabout. Slip road lane 3 must not move right.

Slip road lane 3 should go to roundabout lane 2.

Slip road lane 2 should go to roundabout lane 1. (sometimes can also be a second left turn lane)

Slip road lane 1 must turn left onto A12W.

Roundabout lane 1 would be better labelled as M25N & A12E, allowing both lanes 1 and 2 to go around the next part into the two lanes there, both labelled for A12E.

Then the squabble for one lane moves to the entry into the A12, as the lanes merge to one, rather than on the busier part of the roundabout. As the lanes merge, drivers are generally expecting this, and will mostly act sensibly. On the roundabout, drivers aiming for lane 2, from either lanes 2 or 3 of the slip road, will all think they are right, and the others are wrong, creating a high risk merging point.

Ideally, lane 1 across the roundabout should also turn right, but currently, if using it for this, try not to be alongside anyone, as lane 2 drivers will take either lane across the next part.

As a major junction over a motorway, this is probably the responsibility of Highways England, not the local authority. Might be worth writing to them.

Meanwhile, take care, stay observant, and don't fight. Anyone insisting on being ahead, let them go. It'll make them feel good about their day.
 
And here's an exciting diagram I created to demonstrate how the lanes are labelled and where they propose the traffic go (blue arrows)
You'll have to click on this to make it bigger

You missed M25 south off the pic.

Rules
Enter at 70mph, give way to NO ONE ever! Don't stop for anything or anyone. Use full beam lights and horn and be ready with fingers and gestures.

or

Go another way! I too hate this junction.
 
Complicated junctions can be bad for locals but what about the poor sods passing through for the first time.
Road markings are often covered by standing traffic and you only find your in the wrong lane when it’s too late.
 
Roundabout lane 1 would be better labelled as M25N & A12E, allowing both lanes 1 and 2 to go around the next part into the two lanes there, both labelled for A12E.

Meanwhile, take care, stay observant, and don't fight. Anyone insisting on being ahead, let them go. It'll make them feel good about their day.
This is how I've thought it should be laid out too, it seems very poorly (if at all) thought out. Fortunately I don't really get road rage so I just let people go where they go and slip in behind if I've been forced over, it's still a pain trying to work out what everyone around you is going to do when there is no clear path for them...

You missed M25 south off the pic.

Rules
Enter at 70mph, give way to NO ONE ever! Don't stop for anything or anyone. Use full beam lights and horn and be ready with fingers and gestures.

or

Go another way! I too hate this junction.

I missed both the entrance and exit for the M25 south off because I couldn't be bothered to draw them :p
Both those options sound completely viable for me :D
 
Many years ago I worked for a local authority, they built a junction,
we called it "The Magic Roundabout" later some of the signs had to
be removed as they were not in the highway code or any other code
for that matter, I was told at the time that the bloke that designed
it did not have a drivers licence, this didn't surprise me as when we
had a site meeting he turned up on a bike.
The roundabout was a thing of wonder, still is as far as I know, I
drove it many times a week and was asked a few times "can we do that"
it had 2 concentric roundabouts with some lanes going anti clockwise,
I think they have installed lights now but it was every man for himself
and god help you if you had never used it before.
Here about's they are in the middle of a massive road scheme costing millions
it includes 2 bridges, a mile or two of new road and re modelling three large
junctions, all to remove a bottle neck caused when they narrowed the
road to put in a cycle path that as only been used on opening day for a
photo shoot and as been more or less disused since I cant remember when
I last saw a cyclist on it.
 
I missed both the entrance and exit for the M25 south off because I couldn't be bothered to draw them
Both those options sound completely viable for me

I had to do this journey about 100 times a year for so,me years and I really like your contempt of the bit and that you couldn't be bothered. I concur totally with this assessment. I am so incredibly glad to have retired from the race of rats.
 
Back
Top