A308(M)

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JohnA14J50
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A308(M)

Post by JohnA14J50 »

Having read the story of M4 J8/9, I have to wonder why the effort was made to classify the A308(M) as a Motorway, which presumably took time to obtain the legal order for. Would it not have been simpler to just downgrade what's now the A404(M), instead?
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Patrick Harper
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Re: A308(M)

Post by Patrick Harper »

Both it and the A404(M) were probably conceived as part of orders relating to the M4 extension. Trunk new build all-purpose D2's weren't particularly fashionable (yet).
Last edited by Patrick Harper on Sun Dec 27, 2020 18:13, edited 2 times in total.
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Re: A308(M)

Post by Gav »

ownership resposibilities.

keeping it a motorway meant that the MOT would pay for upkeep ?

Also thats a fair length of road to have to absorb to the local infrastructure.

and the time when this was done motorways were in vogue so they would rather keep a motorway than lose it.
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Re: A308(M)

Post by Steven »

Simpler legally, yes.

But then you'd lose the benefits too - there's no need for all purpose traffic to use it, and it also doesn't protect the road from, for example, the gas board sticking a gas main down it.
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Re: A308(M)

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JohnA14J50 wrote: Sun Dec 27, 2020 16:55 Having read the story of M4 J8/9, I have to wonder why the effort was made to classify the A308(M) as a Motorway, which presumably took time to obtain the legal order for.
I’d be surprised if separate legal orders were made for the A308(M) - my assumption would be that the motorway orders for the M4 J8/9 to Reading, which is the project that created the A308(M), included orders for the roundabout and spur as well. That would mean no effort was required to set the spur up as a motorway. Legal orders were happening anyway.

Conversely, no orders were being published to convert any Special Roads to all purpose roads, so downgrading the A404(M) to a non-motorway road would have required legal orders to be pursued that wouldn’t otherwise be needed.
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Re: A308(M)

Post by Ross Spur »

Gav wrote: Sun Dec 27, 2020 18:12 keeping it a motorway meant that the MOT would pay for upkeep ?
This point did come up at the Side Roads inquiry hearing in May 1968 per the Reading Evening Post but it would seem to be in relation to a proposed spur south from M4 J8/9 to the A330 Bracknell road since reference was made to access to the motorway from Bracknell. The Berkshire County Council witness was asked if the Council's fight to get a spur road at Holyport included in the motorway plan was based on making the Ministry of Transport pay for it instead of the County ratepayers. The Assistant County Surveyor confirmed it was one of the reasons. The question had been put forward on behalf of a group of Holyport residents who were opposed to the spur. He added that whether the spur was to be built as a special road or not, they were interested in the principle that it was necessary to avoid overloading the A330 Maidenhead to Ascot road with traffic.

As ever, the report of the outcome has not been seen. The A308(M) was referred to later as the Braywick Spur.

On the legal documentation side the A308(M) part was part of the scheme for the new J8/9 at Holyport per https://www.thegazette.co.uk/London/iss ... /page/9022 with the opening notice at https://www.thegazette.co.uk/London/iss ... page/13562

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Re: A308(M)

Post by Berk »

This sort of answers one of my questions - i.e. why was the current site of J8/9 chosen away from the old mainline - meaning that a new link motorway (A308(M)) had to be built at great expense, as well as making a short stretch of A4(M) redundant.

Why didn’t they consider a grade-separated junction with the A330 instead?? The area wasn’t particularly built up then - as this well-known movie shows.
It would’ve been easy to build a couple of bridges, and slip roads, and free-flowing access to the old motorway would’ve been maintained - just like the other end of the bypass.

Instead you’ve got a crummy roundabout, and an unnecessary additional motorway back to the A308. If they were particularly concerned about swamping the A330 with traffic, they could’ve made J8/9 an interchange-only junction without slip roads. Driving on to J9a would hardly be the end of the world.
Last edited by Berk on Thu Jul 06, 2023 21:17, edited 4 times in total.
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Re: A308(M)

Post by Berk »

I also understand Berkshire County Council had been working on improvement plans along the M4 Corridor for a long time before WW2. Something broadly similar to the motorway plans.

Does anyone know what they would’ve meant/which corridor it would’ve taken??
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Re: A308(M)

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Berk wrote: Thu Jul 06, 2023 19:47Why didn’t they consider a grade-separated junction with the A330 instead??
Because a junction had to be built where the new M4 branches off the old anyway, which would mean new sliproads at what is now J8/9. The original J8 was closed because it would have been too close. An interchange at the A330 would have been even closer and therefore even less acceptable.
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Re: A308(M)

Post by Berk »

That’s not quite the point, though. Even if J8 needed closing, J8/9 is 1 mile away from where J8 was. It had no road links, so the A308(M) had to be built (even if it was part of the same contract). It seems unnecessarily distant.

Moving it to where the A330 is would be just under ½-mile. And only require limited slips to connect the two motorways. But did it even need replacing at all??

Think about it - you could still keep most of the old mainline, as A404(M), junction 9a is only 1¾ miles away. A fork junction would’ve been acceptable.
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Re: A308(M)

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Berk wrote: Thu Jul 06, 2023 21:09 That’s not quite the point, though. Even if J8 needed closing, J8/9 is 1 mile away from where J8 was. It had no road links, so the A308(M) had to be built (even if it was part of the same contract). It seems unnecessarily distant.

Moving it to where the A330 is would be just under ½-mile. And only require limited slips to connect the two motorways.
OK, I see. One junction at the point where the A330 crosses the M4, which would connect everything together. That would work, but would have been much more difficult to build since it was on the existing line of the M4. By building J8/9 where it is, it could be built in its entirety offline and then traffic switched over, which will have made things simpler and cheaper.
But did it even need replacing at all??

Think about it - you could still keep most of the old mainline, as A404(M), junction 9a is only 1¾ miles away.
Well, I don’t know, except to suggest that it was considered that it was necessary to replace it. Remember that it’s not just about what is practical but also what is acceptable: when the changes were being made, some wealthy and influential people around Bray and Holyport had been used to having direct access to the M4 via junction 8. Making them go much further through Maidenhead itself to reach J9a might not have been acceptable or might not have survived a public inquiry. It would be interesting to see what options were proposed and why this layout was chosen. But, as I say, the conclusion we can draw is that the layout as built, complete with A308(M), was considered acceptable and affordable at the time.
A fork junction would’ve been acceptable.
Not for access to and from the M4 west, especially if you’re closing J8 and not replacing it at all. How are people who used to use J8 and J9 going to head west, if you only allow them access to the A404(M) at 9a, and the A404(M) has only access to the M4 to and from the east?
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Re: A308(M)

Post by Berk »

This is where local knowledge comes in. I am mindful the reason the motorway was routed to the south was because residents of Caversham and Sonning objected to it.

Which suggests that journeys to the north of Reading would be conducted via the A4 and existing roads, like it or not.

This is also where knowledge of Berkshire’s main road improvements would’ve been useful too. Had they planned a new dual carriageway along the current M4, or along the A4 corridor??
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Re: A308(M)

Post by Phil »

Steven wrote: Sun Dec 27, 2020 18:59 Simpler legally, yes.

But then you'd lose the benefits too - there's no need for all purpose traffic to use it, and it also doesn't protect the road from, for example, the gas board sticking a gas main down it.
However it could be argued that making it all purpose would have assisted in allowing some non-motorway traffic to by-pass the centre of Maidenhead and these days its extremely unlikely a utility company would deliberately wish to route a supply pipe under a road (due to all the hassle working on it provides) particularly if there is no frontage development.


Note I'm not advocating this BTW
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Re: A308(M)

Post by nowster »

Phil wrote: Fri Jul 07, 2023 23:12
Steven wrote: Sun Dec 27, 2020 18:59 Simpler legally, yes.

But then you'd lose the benefits too - there's no need for all purpose traffic to use it, and it also doesn't protect the road from, for example, the gas board sticking a gas main down it.
However it could be argued that making it all purpose would have assisted in allowing some non-motorway traffic to by-pass the centre of Maidenhead and these days its extremely unlikely a utility company would deliberately wish to route a supply pipe under a road (due to all the hassle working on it provides) particularly if there is no frontage development.
Having it all purpose would have encouraged frontage development (eg. the car dealership half way up the S2 A601(M) (Deceased).
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Re: A308(M)

Post by Phil »

nowster wrote: Fri Jul 07, 2023 23:33
Phil wrote: Fri Jul 07, 2023 23:12
Steven wrote: Sun Dec 27, 2020 18:59 Simpler legally, yes.

But then you'd lose the benefits too - there's no need for all purpose traffic to use it, and it also doesn't protect the road from, for example, the gas board sticking a gas main down it.
However it could be argued that making it all purpose would have assisted in allowing some non-motorway traffic to by-pass the centre of Maidenhead and these days its extremely unlikely a utility company would deliberately wish to route a supply pipe under a road (due to all the hassle working on it provides) particularly if there is no frontage development.
Having it all purpose would have encouraged frontage development (eg. the car dealership half way up the S2 A601(M) (Deceased).
Not necessarily - Development is not always allowed as permission will depend on other factors and just because a road isn't a motorway doesn't mean there is total freedom to for developers to do what they want.

In the case of the A308(M) then were it declassified then I agree its feasible that someone might want to plonk a roundabout on it for a housing development - but when you consider that access to the land on the south side (sandwiched between the A308(M) and M4) which can easily be accessed from the A330 remains as a field despite the housing shortage prevailing in the SE its not automatic it would happen.
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