A3/M25 Wisley Upgrade

[corders]

personally, the junction would probably get away with just adding a free-flowing left turn from A3 northbound to M25 Westbound if there are any funding constraints

the majority of the A3(N) traffic leaving at this junction is for the left turn, so removing that from the roundabout would hopefully give the right-turning (A3 north to M25 East) traffic more space. less backed up traffic on the off-slip lane, with any luck the middle lane won't get slowed up by people attempting to cut in late

this would also allow the furthest-right lane on the A3(N) off slip to not get squeezed when trying to get to the equivalent lane on the roundabout. if you know what i mean, you'll know the lane on the roundabout doesn't appear until you are a few degrees around it, with the lines for the other lane letting vehicles to your left get rather close (i don't know how to link to streetview, sorry)

[jackal]

If we are able to retrofit full free-flow to an existing junction, whoever's in government, I will buy a hat and digest it.

It wouldn't be too hard, it is done frequently overseas (e.g. in Texas numerous three level 'stack-a-traffic lights' have been converted to fully free flow stacks). First put in direct left turns. Then build two freeflow right turns. These can be over the top a la A2/M25, underneath a la M1/M62, or a mixture a la M20/M25 (of course, these examples have only one direct connector - the extra connector goes in the opposite corner). That leaves you with the roundabout handling only two movements, which can easily be made freeflow with new bridges on the same level as the roundabout.

A3/M25 has very high traffic volumes (A3 alone is over 100,000AADT I believe, M25 over 150,000) and that is only going to increase with growth in the South East and as capacity constraints elsewhere on the M25 are eased. So you could argue that they should go straight for the full upgrade here rather than the usual British approach of tweaking slip roads, then adding left turns, then widening bridges, then when things get really bad put in a freeflow right turn, with massive expense and disruption at each stage, and the junction still congested at the end of it (see M1/M25).

[firefly]

I've found the document - the exact wording is "improvement of the Wisley interchange to allow free-flowing movement in all directions, together with improvements to the neighbouring Painshill interchange on the A3 to improve safety and congestion across the two sites". Widening the M25 to 4 lanes through junctions between J10 and J12 is also mentioned. Both are in the "committed schemes" section - although the entire document has a disclaimer that it was published under the previous government (so I wouldn't hold my breath waiting for the diggers to arrive).

What exactly is wrong with Painshill junction? It looks perfectly fine for me.

Four left filter lanes would be easy enough to do. I'd go for a M25/M1 style junction, with slips from A3N to M25E and M25E to A3S. There would be enough residual capacity on the roundabout to deal with the remaining two movements.

Such a solution would require the additional link roads to be piled up to the 4th and 5th level of this junction. This is certainly not going to happen. If it is intended to make more than one right-turning movement free-flowing then the whole junction will be rebuilt.

The real trigger for a possible junction rebuild is probably the widening of both intersecting mainlines though. The M25 should be D4M through this junction, preferable with clearance for D5M as well, and continuous D3 or D3M wouldn't go amiss for the A3 either. All this could be done by a complete new junction.

[M4 Cardiff]

I think Painshill can get L1 queueing at peak periods, with the associated safety issues, especially with that junction only about mile further up the A3.

[Percy]

Queue leaving at Painshill was back beyond the M25 yesterday evening

[A320Driver]

Received this from my contact at Surrey CC:

The business communities in Woking and Guildford have been lobbying the government and Surrey for investment in the strategic highways network, the rail infrastructure and Heathrow airport. All three transport modes are congested.

Since the general election, the government outside of the restraints of Coaltion has become more motorist friendly!

The County Council has been lobbying the government as well.

The A3 and M25 belong to Highways England and we await their proposals. The County Council will be consulted and I guess we will have a members briefing, like we have had at all stages on the airport proposals.

What we have heard is that 2 options are being looked at in Guildford, an extra lane or a complete new bypass with a tunnel under Hogs Back.

Much of the J10 works are part of the Wisley Airfield development proposal for 2,500 homes.

J 10 to 14 I think are being considered for smart motorway improvements.

So to date no definitive plans have appeared for consultation.

The County Council is engaging with HE already about a new relief road from Woking onto the A3.

So it's early days on the A3 improvements.

[mnb20]

Much of the J10 works are part of the Wisley Airfield development proposal for 2,500 homes.

That's interesting, as currently you can get to Wisley Airfield, in as much as you can get to it at all, from the A3 using Old Lane, the road that leaves the southbound on-slip.

If J10 was replaced by a stack or similar, it is very likely that Old Lane would be stopped up there, but even if it wasn't, access would no longer be possible from the South.

Adding south facing slips to Ockham Park (B2039 junction) might be part of the solution for Wisley Airfield access, but I can't see how J10 is.

[Chris5156]

Adding south facing slips to Ockham Park (B2039 junction) might be part of the solution for Wisley Airfield access, but I can't see how J10 is.

Two reasons, I think. One is that if you're building 2,500 homes right next to the M25 and A3, you need to expect a noticeable increase in traffic on those roads in the immediate vicinity of the development. The other is that any developer building 2,500 homes will expect to have to make a significant contribution to infrastructure in the local area and this represents an excellent opportunity to get some developer funding to pay for the upgrade work that the M25/A3 interchange will need anyway.

[A320Driver]

I agree. Ockham Park and M25 are very close. I can only imagine that some C/D lanes could be planned here, and as you say, South facing slips could be provided very easily at the B2039.

It's clear that Surrey CC are somewhat in the dark as to the actual detailed design but have a clear desire to see improvements.. Watch this space I guess!

[M4 Cardiff]

What we have heard is that 2 options are being looked at in Guildford, an extra lane or a complete new bypass with a tunnel under Hogs Back.

Now I had the same idea on a fantasy map I drew a bit back as part of my ideas for an A3(M) all the way from Tibbet's Corner to Hayling.

I'll try to dig it out when I get home this evening.

For a bit of fun, I'll try and knock up a 'Full Truvelo' for the Ockham, M25 and Painshill junctions...

[firefly]

Much of the J10 works are part of the Wisley Airfield development proposal for 2,500 homes.

Who in his right mind would approve an airfield to be developed by houses that is detached from existing settlements? This area has not only inadequate transport links that go well beyond a few insufficient road junctions. There is also no school or any other place of civic life anywhere near. I suppose that this is intended to be yet another dead-end-development that forces everyone of age to own and to use a car for every single trip. Which in return will fill roads quicker with traffic than new road space could possibly be created.

[M4 Cardiff]

Firefly-

these super developments which basically involve the construction of a new town from scratch do include certain services, such as local shops and a junior school, doctors surgery etc.

The east end of the airfield site is also only a mile from Effingham junction station, so car-less commuting to London, or places on the Guildford - London line is perfectly feasible.
Any bus routes currently serving Ripley, Ockham and Horsley could probably be amended to provide a service to a new Wisley Village should it ever be constructed.

It is certainly not as duff a location for a new town as some I have seen proposed. And it will not result in the loss of prime farmland either.

[A320Driver]

Firefly-

these super developments which basically involve the construction of a new town from scratch do include certain services, such as local shops and a junior school, doctors surgery etc.

The east end of the airfield site is also only a mile from Effingham junction station, so car-less commuting to London, or places on the Guildford - London line is perfectly feasible.
Any bus routes currently serving Ripley, Ockham and Horsley could probably be amended to provide a service to a new Wisley Village should it ever be constructed.

It is certainly not as duff a location for a new town as some I have seen proposed. And it will not result in the loss of prime farmland either.

Exactly right. Locally though this is causing a lot of discussion: I suspect big protests are in the pipeline yet it is actually a very good location for a new town (subject to decent M25/A3 acces!)

[firefly]

these super developments which basically involve the construction of a new town from scratch do include certain services, such as local shops and a junior school, doctors surgery etc.

The east end of the airfield site is also only a mile from Effingham junction station, so car-less commuting to London, or places on the Guildford - London line is perfectly feasible.
Any bus routes currently serving Ripley, Ockham and Horsley could probably be amended to provide a service to a new Wisley Village should it ever be constructed.

It is certainly not as duff a location for a new town as some I have seen proposed. And it will not result in the loss of prime farmland either.

The road to Effingham Junction is not exactly made for pedestrians nor for cyclists, let alone that the station is outside of a reasonable walking distance. And what about school beyond the junior age? Actually, your post confirm that this development is likely to have a lot of short-comings and that is anything but super.

[Stevie D]

Who in his right mind would approve an airfield to be developed by houses that is detached from existing settlements? This area has not only inadequate transport links that go well beyond a few insufficient road junctions. There is also no school or any other place of civic life anywhere near. I suppose that this is intended to be yet another dead-end-development that forces everyone of age to own and to use a car for every single trip. Which in return will fill roads quicker with traffic than new road space could possibly be created.

They're damned if they do and damned if they don't. If they build on existing towns and villages, local residents will be up in arms because the roads and amenities won't be able to cope, and it's changing the nature of their tranquil village, and all the usual stuff.

For significant size developments, new towns are probably a good way to go. You can build new schools, doctors' surgeries etc where you need them, you can build the road and path network as you want it, you're not constrained by the limitations of existing infrastructure. A development of 2,500 houses is easily big enough to support one or potentially two primary schools, a doctors' surgery, a decent bus service, a pub and some local shops.

[Rubberduck]

What we have heard is that 2 options are being looked at in Guildford, an extra lane or a complete new bypass with a tunnel under Hogs Back.

Adding an extra lane up to the A31 Hog's Back junction seems the better option to me. Plus closing the at grade crossings between there and the Stag Hill/Cathedral junction, preferably by giving Beechcroft Drive an over/underpass.

A tunnel would be very expensive and as we've seen with the Hindhead Tunnel liable to frequent closures. Plus I think a lot of the traffic using the A3 through Guildford is probably headed to or from the town itself rather than wanting to bypass it completely.

[sotonsteve]

The problem with the A3 through Guildford is that any widening will involve a lot of compulsory purchase and demolition. The same is true of a completely new alignment, but having a D3 through Guildford won't exactly tick any boxes for reducing segregation and improving the urban realm. In the absence of significant junction remodelling,slip road and side road closures and construction of parallel roads, it won't solve the issue of mixing local traffic with through traffic either.

I guess the question is, what will be easier to build? The A3 through Guildford is only two lanes and generally lacks the cross section for narrow lanes and traffic management to create room for construction/reconstruction. It would probably have to be temporarily rebuilt as a 30mph S4 with narrow lanes in order to facilitate widening works. It would most likely be cheaper and result in a higher standard and more effective solution to just bypass the Guildford Bypass on a new alignment.

[ronA1066]

Can I point you towards the Road Investment Strategy and Road Period 1? The Coalition Government announced last year that they were creating 'Road Periods' to enable funding to be ready for new road projects long in advanced, meaning more schemes will be progressed to construction. Each Period is 5 years long and in this period they are planning on spending £15bn on the network. Any schemes that say they are being 'developed for the next road period' are exactly that. We should see construction on those routes start in the early half of Road Period 2 (2020-2025). That's the plan anyway. The current government show no sign of giving up on this plan.

Welcome to the wonderful world of Control Periods.

The privatised railway has had them since 1996. The theory is fine - in principle, the government decides what improvements it wants and then makes the funds available. Once guaranteed, the funds cannot be withdrawn which gets round the problem of schemes being cut every time the government wanted to cut public spending and suddenly reinserted when more spending was needed (eg to reduce unemployment). Everyone recognises how inefficient this was. The impetus was that Railtrack was a private enterprise company and shareholders needed certainty that its funds weren't going to be switched on and off at the Treasury's whim.

The good thing is that once schemes are allocated to a control period they will happen. The bad thing is that if schemes are not allocated to the next control period you can almost certainly forget about them for at least 5 years.

[ronA1066]

Hi,

The government plans to make the A3/M25 Wisley interchange one with free flowing links, as part of its new 'investment plan', over the next five years.

I was wondering how engineers would actually go about it. Would they use the existing roundabout in a new way and adapt it? Or would they create completely new structures and then remove the roundabout?

Either way it sounds like a big undertaking.

Alex

Interesting. The set up is far from ideal, not least because J10 and Painshill are far too close together, meaning that northbound A3 traffic wanting to exit at Painshill has only a short distance in which to switch lanes into the busy slip road off the M25. The alternative is for Painshill traffic to leave the A3 at J10 and continue straight ahead at the roundabout. Whether that option would still be available with a fully free-flow junction is open to doubt. The only alternative would be to build a flyover to shift A3N to Painshill traffic over to the left.

The reason for this unsatisfactory layout is because the line for this stretch of the M25 was set by Bressey in 1937, though the plan then was to take over the minor road that runs across Ockham Common. (In the event, the motorway was built adjacent to the minor road which still exists and which can be accessed by cyclists and pedestrians off the J10 roundabout.

Which leads me to say that one thing that would need to be sorted out in this new scheme is provision for cyclists and pedestrians. The traffic lights on the J10 roundabout currently include provision for pedestrians and cyclists who are, of course, quite entitled to use the A3. Whilst they may be few in number, they would otherwise be faced with a lengthy diversion. The pedestrian/cycle phase was added to the lights (IIRC) when an elderly cyclist proceeding northbound along the A3 (having to use Lane 2 to reach the flyover) was hit by a car crossing to the M25 on-slip at the last minute. If there is no provision for cyclists at this junction then they will once more be faced with the need to get out into Lane 2 of the A3 to cross the M25. Or will the scheme include a grand network of subways beneath the whole junction? I can see this taking all the funding available for Period 2.

[firefly]

The problem, as described above, is Painshill Roundabout, which needs to be widened at crucial points or relieved. The de-weaving of traffic streams between Wisley and Painshill Junctions, however, doesn't help solving these capacity constraints.