M25 Junction 10 to Junction 16 Smart Motorway

[jackal]

This now has a scheme page:

http://roads.highways.gov.uk/projects/m ... -motorway/

The scheme is notable for having the first section of D5ALR (five lane all lane running). Once the concept is proven there are many other D4Ms that could benefit from the extra running lane.

It will also widen the M25 to D4ALR within J10, J11 and J12, creating a long stretch of continuous D4+. I do wonder if a lane drop at J10 and J12 northbound is actually justified given the volumes of turning traffic, though.

[fras]

This now has a scheme page:

http://roads.highways.gov.uk/projects/m ... -motorway/

The scheme is notable for having the first section of D5ALR (five lane all lane running). Once the concept is proven there are many other D4Ms that could benefit from the extra running lane.

It will also widen the M25 to D4ALR within J10, J11 and J12, creating a long stretch of continuous D4+. I do wonder if a lane drop at J10 and J12 northbound is actually justified given the volumes of turning traffic, though.

Its getting like Los Angeles !

[Johnathan404]

I assume this section still has continuous hard shoulders, as J9-10 doesn't.

I'm more curious that the web page is roads.highways.gov.uk . What other subdomains do they have?

[jackal]

Aside from short sections inside junctions, it's only J15-16 that's getting ALR under this scheme, and that mostly has hard shoulders, though some bridges will need widening/replacing.

[Glom]

There were a lot of cars on hard shoulders in this section this evening. Don't know how we'll cope without them.

If some bridges need replacing anyway, please make them wide enough for more than just the extra lane.

[bart]

There were a lot of cars on hard shoulders in this section this evening. Don't know how we'll cope without them.

Yes, there is far more traffic on a D4M than a D3M (Peterborough to Alconbury excepted) so you expect more breakdowns and more accidents. Having ERAs more closely spaced on a D5ALR road would seem prudent.

[RichieGraham]

Having ERAs more closely spaced on a D5ALR road would seem prudent.

They could make one long continuous one and call it something, I don't know, like 'hard shoulder'?

[Patrick Harper]

After this scheme is complete, the next major pinchpoint will be the D3M through J20, and I have no idea how this could be sorted out.

[Arcuarius]

Having ERAs more closely spaced on a D5ALR road would seem prudent.

They could make one long continuous one and call it something, I don't know, like 'hard shoulder'?

And then use it as a traffic lane! Brilliant!

Or, and here's a radical idea, maintain and refuel your vehicle sufficiently that it never breaks down!

[jackal]

After this scheme is complete, the next major pinchpoint will be the D3M through J20, and I have no idea how this could be sorted out.

11-12 could probably do with five lanes.

[Bryn666]

Or, and here's a radical idea, maintain and refuel your vehicle sufficiently that it never breaks down!

And you've never had an unexpected tyre failure, or other vehicle based emergency I take it...

[Chris Bertram]

Or, and here's a radical idea, maintain and refuel your vehicle sufficiently that it never breaks down!

Yeah, that would have worked when my turbo failed on the M54 near Wolverhampton, despite my car being serviced at all appropriate intervals. I've never been so thankful for AA membership.

[A9NWIL]

Well now here is a thing! What do they do when they realise that D4 ALR isnt enough and they need a new lane? Yes thats right once all the HSs on all busy motorways are gone and they are still busy then traditional widening is the only route! Saving money? I cant see it in the long run, they should have just made a new shoulder each time.

The M25 will likely end up with D5 all the way round eventually, with loads of bridges being replaced.

TBH they are better off pushing though new motorways elsewhere and finishing parts of ringway 4 where they can, even if they have to tunnel under some of west London in places.
Ringway 4 would alleviate the M25 of some more local journeys, also with a new lower Thames crossing the M26 could be upgraded and linked to that, becoming the new M25 in the process. A new outer bit of ringway 5 in north east London could be built and take the M25 number. Ringway 4 could become the M15, or was it the M16 I cant remember which it was orignally planned to be, with the link in the south east between the two rings becoming the M21. The north link bit could become the M125.

[Jayck]

What seems odd to me about this scheme is that they seem happy with D5 ALR between J15 and 16 but aren’t going for D5 between junctions 10 and 12. That stretch is at capacity for most of the day in the summer months, so surely while Highways England are set up down there they should do the job properly rather than just have to come back another few years after completion? With Heathrow expansion and population growth something is going to have to give eventually.

I’ve also noticed that HE have been very quiet about this scheme for a while now, anyone reckon they might be having a rethink? It would seem sensible to tie it up with the proposed re-alignment outside Heathrow between J14 and 15, or perhaps they’ve kicked it into the long grass until the RIS2 scheme is unveiled

[jackal]

J10-12 has highly discontinuous hard shoulders and is also partly urban, making widening more problematic in terms of land take and emissions. I think they have concluded that it is not feasible to widen and are just trying to squeeze out the last drops of capacity with the widening within junctions.

[Jayck]

That's a pity if so, there's something frustratingly short-termist about the M25 strategy. Do the maths and look at the amount of new houses they're building in the region, its not long before bits of the M25 could be seeing 300,000 vehicles a day which compares to some of those mega highways they have around LA. My sense is that they should stomach the difficulties of taking in extra land in the short semi-urban sections and make it six full lanes Junctions 10-12 and Junctions 15-16, while Junctions 12-15 need to be full US style interstate with collector lanes and what have you. Now, I realise that's not going to happen but I do believe it would be cheaper in the long run and ultimately cause less damage by bypassing the need to build new roads across unspoilt countryside... perhaps it's good I'm not in charge.

Highways England rules out further widening partially because the road would "become difficult to navigate", but they manage perfectly well in just about every other developed country, why can't we?

[DB617]

It's quite right to observe that ALR widening is in a way kicking the capacity can down the road, IMO. However it's prudent also to ask whether there's really a problem with this. If the current Govt feels it cannot invest any more than it already is at present, due to policy or economy (more likely the former in the 2010-2019 period) then ALR is at least doing *something* to improve capacity. Widening is still possible later.

[Jayck]

Well of course you're right and in tune with how things actually get done. But given that we effectively know something drastic needs doing in future surely its cheaper to just do it in one fail swoop, rather than split it into two major projects the second of which effectively undoes the first.

[DB617]

Well of course you're right and in tune with how things actually get done. But given that we effectively know something drastic needs doing in future surely its cheaper to just do it in one fail swoop, rather than split it into two major projects the second of which effectively undoes the first.

Certainly makes sense from an engineer or even financier's point of view. Sadly this is not Government policy and probably even an investment-happy one would balk at the idea of spending money on future proofing. After all, most of the time the future is another person' problem, and this is where Civil Engineering is intimately intwined with politics.

[Micro The Maniac]

The page states:

A separate strategic study is looking at longer term options to improve the performance of the transport network between junctions 10 and 16 of the M25.

If this is indeed a "strategic" study, hopefully it will rule out just adding more lanes to the M25, and put serious consideration to both of:

• Upgrading the A404/A404(M) to full motorway rules from the M40 to the M4
• Extending the A329(M) south from the M4 around the west of Bracknell then, either/both of
  • along Old Wokingham Road, Foresters Way (A3095) to pick up the A331 to the M3 and A31, or/and
  • around to the A322, between Guildford and Woking, south of Wisley airfield before they build on it, to pick up the M25 just east of the new Cobham Services
  You could call this the M31 ?
• Upgrading the A34 from Winchester to Wendlebury to D3M as a minimum

Perhaps I need to go a few doors down, to the Fantasy forum?