M25 J4 link - is it M25, is it A21?

[Fluid Dynamics]

So we have

1) Chopsticks at the A21/A224 roundabout with "M25" (ditto at Sevenoaks J6)

2) Signs on M25 indicate it to be A21(M) due to signing it as A21 not (A21)

3) Whatever it is, it is the (A21) as the old A21 is A224 and the M25 immediately becomes the A21 at the chopsticks at Sevenoaks.

4) The roundabout A21/A224 does NOT have a junction number (ie the equivalent roundabouts on the Luton airport spur /Gatwick Airport spur on the M1/M23 are numbered as part of those motorways ie 10A 9A

5) Maps show it as M25

6) At junction 6 the main line of the Road is signposted as "Sevenoaks, Hastings A21" despite the fact that it is on an even longer spur


1) Can be dismissed as exactly the same occurs on several other sites to avoid confusion (eg the now gone and unlamented M15 was signed as Junction 3 of the M11 with M11 chopsticks to avboid confusion)

5) So can (5) as maps are not reliable in this (try finding A14(M) on a map)

The balance of probability tilts towards A21(M) at both ends as given that the motorway is M25(A21) between J5 and 6 if the spurs are M25 they should most certainly be signed as (A21) but that is not really enough proof

So lets head south from that last google link...

Hmm this looks interesting.

Note the slip road states states M25 Gatwick (M23) Heathrow (M4)

Therefore the main line of the road should state M25 Sevenoaks (A21) Hastings (A21)

But it actually states (in Blue) A21 Sevenoaks Hastings

Even more interesting, this spur is over a mile long and has its own junction. If it is part of the M25 why does that junction not have a number, and why is there only "A25" for the slip road and no number for the main line at all on that sign?

A bit further on thats a bit better and would be consistent with the motorway being M25 so perhaps it is M25 after all?

But wait

take a closer look

* That sign says for the main line "Hastings A21" in green

* but it says for the first slip, which is before the end of the Motorway "Sevenoaks Riverhead A25" in a white box on a blue background.

If this stretch of road was the M25 then this sign would state M25 Sevenoaks (A25) Hastings (A21)

It does not, it states A21 Sevenoaks Hastings

And here is confirmation that you turn off for sevenoaks onto the A25 prior to the end of Motorway regulations (just)

And of course when that stretch of road opened it WAS the A21 as it was built before the M25. It was part of the A21 Sevenoaks Bypass and was placed under motorway regulations some years later when the M25 was built, hence the substandard hard shoulders.

Therefore that stretch of road can only be the A21(M)

I declare a secret motorway

Bravo. I'm not convinced by the J4 spur being the A21(M), but by god junction 5 should be. It is signposted as the A21, has its own Motorways merge signs sounthbound, Southbound is the mainline and has its own GSJ junction. Easily up their with the A14(M). Extend it to Tonbridge I say while we are on the subject, its such a good piece of road.

[Steven]

There's no route confirmation signs, documenation or mapping evidence. Sorry - A21(M) it's not.

[Fluid Dynamics]

There's no route confirmation signs, documenation or mapping evidence. Sorry - A21(M) it's not.

I have no evidence that it is the A21(M), I just think as a regular user of this route it has as good as (or even better) claim than the A14(M) if these things were based on any 'standardised' benchmark. Its certainly more than just slip roads.

What annoys me about J5 is that southbound the A21 ( straight on) still shows up on sat navs as the M25, which confuses many people. If you add to this the Eastbound M25 TOTSO then this is the junction that I regularly hear people have got wrong. I think designating the route to the A21 as the A21(M) would make things a lot simpler.

[Stevie D]

The one thing I don't get is why the junctions for these spurs seem to use roundabouts. Why not use a trumpet? That way you only need to build one bridge. I said the same thing about the Gatwick spur junction and submitted it as a bad junction.

Apart from the land-take issue, trumpets have their own problems due to the tight radius of the sliproads. The epitome of this is M6 J15, which has a huge problem with lorries overturning. Regular sliproads to/from a roundabout are much safer, because there turns are taken at a much lower speed, and don't require traffic to leave or join the mainline on the way in or out of the curve.

A further factor that might come into play at some junctions might be that roundabouts are much easier to tie other roads into than trumpets. For example, if M5 J31 had been built as a roundabout interchange, it would be very easy to add a link to the A379 bypassing Exminster and improving access to the Dawlish area considerably. But because it has been built as a trumpet, any such link road would require the complete reconstruction of the junction, so is far less likely to happen.

[A303Paul]

There's no route confirmation signs, documenation or mapping evidence. Sorry - A21(M) it's not.

Is there any documentation that this has ever ceased to be the A21, which it was when it opened and remained so for years afterwards before having its green signs replaced with blue ones (and that was just about all they did)?

How do you explain the signing of "A21 Sevenoaks Hastings" in blue when the A25 turnoff for Sevenoaks is prior to the end of the motorway?

And what is a damn great gantry placed over the road, after the M25 turns off, with "A21 Sevenoaks, Hastings" in blue if not a route confirmation sign (albeit without mileages)

[Halstead]

There's no route confirmation signs, documenation or mapping evidence. Sorry - A21(M) it's not.

I have no evidence that it is the A21(M), I just think as a regular user of this route it has as good as (or even better) claim than the A14(M) if these things were based on any 'standardised' benchmark. Its certainly more than just slip roads.

M25 J4 is a basic spur, presumably it takes up pointless paperwork giving its own number, although personally I never cared at all and always saw it as part of the M25.

The only aspect of the spur I find difficult to gather are the non-motorway provisions where the A224 is supposed to follow the M25 as if it were a non-primary A21. Apart from the tiny triangles on the signs, the only references s/bound of being a non mway route are around Badgers Mount, before vanishing south of the area where the driver has the choice of taking the A25 at Riverhead or driving through Sevenoaks.

If there were any chances for motorway provisions down to Tonbridge, I would certainly press for the road south of J5 for a new number, just to reduce its confusing disposition, as well as trying to make M25 J4 less ambiguous, but mainly to prevent endless discussions about this tiny spur cropping up in future.

[RichardA35]

There's no route confirmation signs, documenation or mapping evidence. Sorry - A21(M) it's not.

Is there any documentation that this has ever ceased to be the A21, which it was when it opened and remained so for years afterwards before having its green signs replaced with blue ones (and that was just about all they did)?

Yes, London Gazette notice

[A303Paul]

OK , as I see it


It IS the A21(M)

I found the order in the London Gazette

The M25 (Swanley to Sevenoaks Section)(Side Roads and Transfer) Order 1977

"This transfer to Him [the Minister of Transport] as part of the above mentioned motorway and connecting roads, the length of the Sevenoaks Bypass (A.21) between it's junction with Pilgrims Way and it's junction with the southbound exit sliproad connecting the A.25 road (eastbound) at Chipstead and the two slip roads connecting that by-pass with the A.25 at Chipstead."


So Under the orders

The A.21 section decribed became a trunk road

Either as the "Motorway" or as a "Connecting Road".

The part that is the main line of the M25 is clearly the "Motorway"

The part that is a spur is obviously a "connecting road"

The order says nothing about existing connecting roads being renumbered.

Therefore it remains the A.21

Clause 1 of the The M25 (Swanley to Sevenoaks Section) Order 1977 (same page), states that said part of Sevenoaks bypass is to become a special road

Therefore, I believe there is more than sufficient evidence in both the government orders and the signing on the southbound carriageway that it is indeed the A21(M)

Clause 2 of the latter order would appear to imply that the spur from J4 to A21/A224 at Knockholt is not part of the A.21 but I can't find anything to support it being neccisarily part of the M25 either, so perhaps it is another unclassified motorway like the Walton Summit motorway?


Richard, you provide a different, later, london gazette link, this (clause 1) talks about a route "provided by the M25 Motorway (Swanley to Sevenoaks) Scheme 1981...stating at [the swanley junction and] proceeding to join the existing A21 Sevenoaks Bypass... then proceeding along the existing bypass". It does not say anything about that bit of the Sevenoaks bypass ceasing to be the A21, only (in the preamble) that it becomes a special road on the said date.

Indeed the order you link to could be seen to imply that the main line of the M25 north of Junction 5 as far as Pilgrims Way is actually not M25 but A21(M)!

At the root of it is that it is almost unique for a longish stretch of A road to become a motorway without being rebuilt, just by changing the signs. The draft orders do not seem to have considered fully the situation of a "connecting road" that is upgraded to special road, already having its own road number due to being pre existing and have not therefore included provision to renumber it.

[crazyknightsfan]

What have I done?

There's no...documenation

I was hoping you might know as much.

I am also following A303Paul's posts with interest...

[Bryn666]

I think you are reading too much into it.

Special road orders do not enshrine a number. There is no A21(M) because it is simply a spur off the main M25 that links to the A21. It being an upgraded A road is irrelevant.

By extension your logic is telling us the Chandler's Ford bypass is actually the A33(M).

[A303Paul]

I think you are reading too much into it.

Special road orders do not enshrine a number. There is no A21(M) because it is simply a spur off the main M25 that links to the A21. It being an upgraded A road is irrelevant.

By extension your logic is telling us the Chandler's Ford bypass is actually the A33(M).

Bryn, interesting comment, however by your logic, the A14(M) would be part of the A1(M)?

[nowster]

Special road orders do not enshrine a number.

Nor do they necessarily make a road a motorway...

[Bomag]

On HAGIS, SMIS, HAPMS this link is catogorised as the M25; the reference number for hollow lane footbidge is right for the M25.

Signing is designed to maximise comprehension. Even if designed properly you cannot use what is on the signs to argue or confirm anything.

[A303Paul]

On HAGIS, SMIS, HAPMS this link is catogorised as the M25; the reference number for hollow lane footbidge is right for the M25.

Signing is designed to maximise comprehension. Even if designed properly you cannot use what is on the signs to argue or confirm anything.

Interesting, thanks. If that is so about the signs then we can say goodbye to the 'route confirmation sign' principle in which case there will be a few deletions on pathetic motorways of A167(M) etc.

The reference to SMIS etc. Is interesting but how do we know they are right? As I understand it, with a special road it is the legal orders that count. If the orders were not done properly then the chandlers ford bypass would indeed by the A33(M) and part of the M25 would be the A405(M) whatever other documentation said.

[wrinkly]

As I understand it, with a special road it is the legal orders that count. If the orders were not done properly then the chandlers ford bypass would indeed by the A33(M) and part of the M25 would be the A405(M) whatever other documentation said.

No, the special road orders do not have to mention a road number, and in the early days they usually didn't. In more recent years the orders usually have a number (and the word "motorway") in the title of the order, but they don't contain a clause saying that the road has to be known by that number, and neither do the acts under which the orders are made. The title of the order is just a tool to facilitate reference to the order.

As Bryn says above, special road orders do not enshrine a number.

[A303Paul]

No, the special road orders do not have to mention a road number, and in the early days they usually didn't. In more recent years the orders usually have a number (and the word "motorway") in the title of the order, but they don't contain a clause saying that the road has to be known by that number, and neither do the acts under which the orders are made. The title of the order is just a tool to facilitate reference to the order.

As Bryn says above, special road orders do not enshrine a number.

ok then, if the special order is not what defines it's number, and the road signs can have false numbers to avoid confusing people the what does define the number?

Or in this case what changed the number of this stretch of road from it's original number of A21 to M25

ditto all the other "secret numbers" found in the motorway network eg A14(M) A167(M) some of which are barely two hundred metres long, appear in no maps at all and no sign at all or just a single route confirmation sign which happens to have a blue background, yet are accepted as existing?

or does someone here have divine authority to decide, because what I am seeing is so many inconsistencies I am beginning to wonder if that is the case?

[Bryn666]

The DfT keeps an out of date list of road numbers. That is the divine authority - and how things like the A635(M) were discovered. Welcome to UK Government; a total mess and no coherence.

There just is no evi dence of the A21(M) anywhere. The A1058(M) on PM refers to an abandoned project for which 150 metres exist.

The A14(M) has been referred to by the HA.

No one has ever mentioned the Orpington or Sevenoaks spurs.

[wrinkly]

This relates to a point Debaser has just made on another thread. There seems to be a tendency on SABRE to assume that questions have well-defined, clear-cut answers, whereas in real life they often don't.

[A303Paul]

This relates to a point Debaser has just made on another thread. There seems to be a tendency on SABRE to assume that questions have well-defined, clear-cut answers, whereas in real life they often don't.

Indeed, so you have to look at the evidence, collate it and make a judgement, which I did and deemed the knockholt spur as M25 and the sevenoaks spur as A21(M).

Others may disagree and I suppose it it quite irrelevant, unless of course you happen to own a web site all about the uks crappy motorways and equally crappy motorway motorway numbering schemes, in which case your decision might be of more importance, especially if the authorities own records are as bad as is claimed in some quarters in which case they probably look at said website to find out the answer themselves meaning that said website might well be the official record unofficially

[Bomag]

All you need to change a route number is the relevant form (Roads 355 AFAIR) and somebody with delegated rights. When I condemned the A102(M) to oblivion the most difficult issue was to get a copy of the form!