M25 Heathrow Tunnel

[kit]

You get the feeling that once Heathrow have a firm go ahead they'll suddenly decide that actually the M25 needs improving to cope with the extra traffic and HE/government need to start putting money in too.

[si404]

You get the feeling that once Heathrow have a firm go ahead they'll suddenly decide that actually the M25 needs improving to cope with the extra traffic and HE/government need to start putting money in too.

Heathrow have been open about this for years. They challenge the cost of how much taxpayer money Heathrow R3 would cost for transport improvements, but they make no bones about it that it will very much be the taxpayer who picks up most of the tab as they refuse to pay for things that aren't either linking the airport to a main motorway or railway, or something directly to do with the construction of the runway.

Given they managed to reduce their Crossrail contribution to zero, and then threatened to charge high access fees for Crossrail trains to reach Heathrow, it's unsurprising.

Compared to Heathrow, Gatwick have a smaller demand list from the DfT and will contribute more to it.

[owen b]

Stansted is a no go - yes there may well have been plans just like there were once plans for the motorway box and all sorts in London - they aint going to expand a tiny airport far removed from London when they have the option to expand Heathrow.

I wouldn't call Stansted tiny. The footprint of it is big, judging by the OS 1:50,000 it's as big as Gatwick and more than twice the size of Luton. It also had the fourth highest passenger numbers of UK airports in 2015. I agree the location isn't great but it's better than Garwick for most people north or east of the M40 axis. The land north and east of Stansted is relatively flat and sparsely populated compared to most places around London. I'm not advocating Stansted, but I can see why it might be appealing in various respects.

[sotonsteve]

I would argue that Heathrow doesn't have the infrastructure already in place for expansion. Yes, it is well located on the motorway network, but this small part of the motorway network is amongst the most congested in the country, even though it has had lots of money lavished on it already. Despite having variable speed limits and having been widened twice near Heathrow, the M25 is still a congested nightmare that is to be the subject of a study into how to increase capacity further. The M4 near Heathrow, which has also already had widening done, is soon to be converted into a smart motorway. The M3 approaching the M25 is also subject to smart motorway works. The local roads are not great either.

All these lack of capacity issues are existing issues. Forget Heathrow expansion, the roads around Heathrow struggle to cope now. As I said, it may look close to a lot of blue lines on a map, but on an interactive traffic map many of those blue lines turn red or black for large parts of the day.

As for rail, at present Heathrow only got connected to the national rail network in the late 1990s, and still only has services going into and out of London. Yes, there are plans for a link to Reading and for Crossrail to go into Heathrow, but it still isn't great. Gatwick has always had better railway connectivity, being situated on a mainline, and Stansted got a rail connection before Heathrow.

[KeithW]

As for rail, at present Heathrow only got connected to the national rail network in the late 1990s, and still only has services going into and out of London. Yes, there are plans for a link to Reading and for Crossrail to go into Heathrow, but it still isn't great. Gatwick has always had better railway connectivity, being situated on a mainline, and Stansted got a rail connection before Heathrow.

Stansted had a rail connection before there was an airport or even aeroplanes
A railway station named Stansted opened at what is now called Stansted Mountfichet in 1845, the current airport station is simply at the end of a short spur from that old station

[Johnathan404]

Yes, and Stansted Express is a good service, but taking all your holiday luggage on the underground to Liverpool Street isn't. Gatwick wins here in that having local services from Clapham Junction (when they're running) allows National Rail connections with much of the country.

A network of coach services to Stansted, with the ones from the south calling at Victoria on the way, is probably the better option.

[BF2142]

Stansted is a no go - yes there may well have been plans just like there were once plans for the motorway box and all sorts in London - they aint going to expand a tiny airport far removed from London when they have the option to expand Heathrow. Heathrow is what is going to be developed. Another runway in there and its got all the roads already there, plus its a major industry hub for the airport they aint going to move all of that away - way too much and it would destroy a lot of the business around heathrow as it is.

I think what would happen is that Stansted and Gatwick would be developed and services progressively transferred from Heathrow over many years. There are very real physical and political constraints to ongoing Heathrow expansion. The urban spider's web has closed in on the airport and development costs just become more and more expensive and protracted. How long has the "new runway" been on the cards now? It is no closer to construction that it was twenty years ago.

[Gav]

Heathrow - its where it will happen.

[Vierwielen]

I would argue that Heathrow doesn't have the infrastructure already in place for expansion. Yes, it is well located on the motorway network, but this small part of the motorway network is amongst the most congested in the country, even though it has had lots of money lavished on it already. Despite having variable speed limits and having been widened twice near Heathrow, the M25 is still a congested nightmare that is to be the subject of a study into how to increase capacity further. The M4 near Heathrow, which has also already had widening done, is soon to be converted into a smart motorway. The M3 approaching the M25 is also subject to smart motorway works. The local roads are not great either.

All these lack of capacity issues are existing issues. Forget Heathrow expansion, the roads around Heathrow struggle to cope now. As I said, it may look close to a lot of blue lines on a map, but on an interactive traffic map many of those blue lines turn red or black for large parts of the day.

As for rail, at present Heathrow only got connected to the national rail network in the late 1990s, and still only has services going into and out of London. Yes, there are plans for a link to Reading and for Crossrail to go into Heathrow, but it still isn't great. Gatwick has always had better railway connectivity, being situated on a mainline, and Stansted got a rail connection before Heathrow.

I live close to the Surrey/Hampshire/Berkshire meeting point. A few years ago I had a contract in Germany and often had the choice of flights from either Heathrow or London City. London City was much less stress. Out of the airport (a short walk) and onto the DRL. An easy change at Canning Town (down a flight of stairs) and pick up the Jubilee line to Waterloo. Very little waiting around wondering if the public transport is going to arrive. Going via Heathrow meant much longer queues, much more walking and much more waiting for the half-hourly bus to Woking and the risk of getting caught up on the M25.

[Glom]

The decision on the M25 is due today. By that I mean Heathrow, but it is the M25 we care about.

I think they should go with the Heathrow braided plan, but extend the C/D lanes through the stack, picking up M4 North facing slips before finally merging onto the mainline. Then the M25 should be widened to 5 lanes to the M40 with a lane dropped for both slips.

[jackal]

I think they should go with the Heathrow braided plan, but extend the C/D lanes through the stack, picking up M4 North facing slips before finally merging onto the mainline.

The mainline volumes within a junction are necessarily lower than they are outside it, but you want four carriageways inside and two carriageways outside?! It would also require the stack to be demolished.

The actual current design is far more sensible, i.e. inner carriageways for M25 mainline, outercarriageways for M4:

Sadly there is talk (see previous page of this thread) of cost-savings, including rerouting the M25 to the west of the new runway. I worry this would butcher the stack and remove the planned freeflow ramp to the A3113, leaving us with a mess like the earlier proposal.

Then the M25 should be widened to 5 lanes to the M40 with a lane dropped for both slips.

As part of the separate M25 junctions 10 to 16 scheme this is being made 5 lane ALR/HSR - the first in the country, I believe.

[Comstock]

The decision on the M25 is due today. By that I mean Heathrow, but it is the M25 we care about.

I've already said all I intend to say on airport expansion, but I do feel sorry for people living near Heathrow. They have been seriously messed about- first it was yes under Blair, then it was no under Cameron, now it looks like yes again under May

[Glom]

My thinking behind quadruple carriageway through the stack is less about capacity and more about having a single merge following that mess. That coupled with a crayonista hope that it would be possible to thread the needle.

And speaking of Heathrow and your link, what has happened about the M4¿

[jackal]

My thinking behind quadruple carriageway through the stack is less about capacity and more about having a single merge following that mess.

Under the current proposal there is no new M25 mainline merge in the vicinity of the stack. The outer carriageways simply disappear off down the M4. It's by far the most elegant solution, and well matched to the volumes (a high proportion of traffic turns for the M4).

You can see the full details of the proposed road layout here (p. 18 on PDF). If you zoom in you can even see lane allocations.

And speaking of Heathrow and your link, what has happened about the M4¿

There's an M4 smart motorway scheme and a small scheme at the Heathrow roundabout but I don't think the M4 layout is affected by the big announcement today, aside from the south-facing slips at the stack now feeding into the outercarriageways.

[Bryn666]

Predictably there is already the start of a backlash over this, I don't think it's a done deal yet.

The road improvements would be nice even without the sodding airport though

[M4 Cardiff]

So that's 10 years of not being able to drive anywhere with a reliable journeytime in west London and parts of Berkshire / Buckinghamshire then

And if Brexit goes trough, will we even need it, or be able to afford it?

[roadtester]

And if Brexit goes trough, will we even need it, or be able to afford it?

I think the opposite.

Currently we are the most flexible country inside the single market, a massive advantage that allows us to carry weaknesses like a limited motorway network and inadequate airports without losing out too much.

Once we are out we will lose that big advantage and those weaknesses hold us back badly. We will have to address them and be seen to address them in order to maintain confidence in our economy. Brexit will turn out to have been very bad for Nimbys.

[Glom]

So that's 10 years of not being able to drive anywhere with a reliable journeytime in west London and parts of Berkshire / Buckinghamshire then

And if Brexit goes trough, will we even need it, or be able to afford it?

Yes, it has been 10 years of not being able to drive anywhere with a reliable journey time in West London and parts of Berkshire and Buckinghamshire.

I wonder what the next 10 years will be like.

[si404]

It's by far the most elegant solution, and well matched to the volumes (a high proportion of traffic turns for the M4).

It's matched to the proportion of traffic volumes, but not the volumes themselves. It adds 1 lane, and let's say removing the weaving adds another lane's worth. The 14-15 bit of M25 is notorious now: how will it be with not just the additional T6 traffic, but T2/3 traffic routed via it as well? You are basically tripling the airport traffic on that bit of M25, but only doubling the link capacity (on top of the through capacity).

At least Heathrow have the decency to pay for the upgrade, even if it is inadequate, but it seems mostly to do with them having to rebuild the road anyway.

Predictably there is already the start of a backlash over this

Arguably the announcement is the true start of the debate, and - whatever the Government decided - it always would have been.

[Arcuarius]

Stansted. Stansted Stansted Stansted.

It's not difficult to spell, and if you're not sure get on Google and look it up!

Sorry, but my goat has just been got.

I'm glad I'm not the only one!