How the Motorways were Numbered

Decision Time - 6th September 1960

J. Riach states the utterly obvious...

A decision is needed on whether we should use the tree system or the sector system for the numbering of motorways.

I am attracted to the tree idea expounded so clearly by the engineers in minutes 24 to 31 and in the plan pinned opposite. Mr Lovett in minute 34 sets out the advantages, as he sees them, of the sector system over the tree system. The arguments for and against are finely balanced but I would come down in favour of the tree. It is true that there are already two departures from that principle in M45 and M62 but I do not think that these need affect the decision. Absolute perfection will not be achieved whatever system is used.

On the lesser point of the numbering of the North and South Orbital, I think there is merit in making it M25 for the reason Mr Lovatt gives and also for the fact that it will reduce the drain on the M10 series of numbers to which attention is drawn in minute 34. I do not think it would be an advantage to split the number according to whether the road runs north or south of the river. It is easier to get to know the one number.

It seems that even the men from the Ministry are starting to get bored with the whole thing! Mind you, writing memos about the need for a decision don't seem like the most productive use of time...

4th October 1960

J. S. Garlick:

As this subject has been my responsibility for only four weeks and as the decision which is now taken is going to set the detailed pattern of motorway numbering for the future, I thought it would be inappropriate for me to make a strong recommendation one way or the other on this problem.

As I see it, an important element in considering this motorway numbering problem is still missing. The academic and some of the practical arguments for and against the two alternatives are well marshalled on this file but I do not think there is sufficient evidence about the rival merits of the two systems from the point of view of road users. The importance of any system being helpful to road users is recognised. But although this criterion is recognised we do not seem to have much indication of which system, if either, would help the traveller more.

The biggest planners of routes in this country must be the A.A. and R.A.C. They have already been told of our decision over motorway numbering and I think that in fact this letter commits us to the "sector" system. Nevertheless if we are considering seriously the adoption of the "tree" system I see no great objection to consulting the A.A. and R.A.C. I suggest, therefore, we should write to them asking for any views they may have on which system would be of more help to ordinary road users.

With that information and the arguments already set out on the file, it should be possible to reach a decision on this.

More sensible suggestions here. Instead of sitting in their ivory towers, they're thinking about talking to the folk who actually have to deal with road numbers on a day-to-day basis.

Again, as an aside, J.S. Garlick eventually became Permanent Secretary of the Department of the Environment, and was a key figure in progressing the M25 toward construction. A copy of his obituary can be found here.

24th May 1961

T. K. Burdess

I am not convinced that the tree system and the sector system are incompatible. In fact at Min. 24 I stated that I was fully in agreement with the sector system except for spurs off the main motorways.

Both systems come unstuck when choosing a number for the Lancs. - Yorks. motorway. It already has two numbers M62 and M19. It may now cross M6 to Liverpool. So the Stretford - Eccles should be renumbered so the M62 can continue west. It might be worth while breaking the rules by continuing M62 numbering to Liverpool.

Mr Lovett's point about running short of numbers for spurs in not entirely valid because we can always resort the 3 digits.

Flippin' heck! They're still going on about it! No-one seems to have listened to the "get on with it" memo from six months previous. So now, we have a new idea - a kind of mixture of the two ideas. Oh, and yes, three digits are suddenly OK.

I don't know about you, but my head's spinning!

17th July 1961

W. Downie

You left the file with me after discussing the numbering system. I see nothing wrong with your suggestions, but I did say I do not like the (M) in brackets on Trunk Road By-passes. If these roads are Motorways why cannot they possess all the dignity of numbering instead of appearing as poor relatives?

I also thought that your M18 should be M1 and A1(M) also named M.1. Your Sheffield - Leeds M1 could be M18. I have in mind the dominance of the figure 1 in M1 and A1. M1 has left A1 at Hendon and should rejoin A1 as M1 north of Doncaster. The whole of Doncaster By-pass to be M1. There is also the Darlington By-pass which I hope you are going to give an M number.

Similarly Denham - Stokenchurch is a respectable length of Motorway (21 miles) and could be M40.

Maidstone By-pass as M.20? You have M.23 alongside A.23.

Hang on a minute - I thought we'd dealt with the Ax(M) numbers!

So much for that seeming agreement. Mind you, I think a large number of people might just agree with Mr. Downie...

20 July 1961

T. K. Burdess

When you and Mr Patterson are ready to do so, I am sure Mr Downie and I will be happy to discuss and hammer out the rather tiresome details.

20th July 1961

J. Riach

By all means let us discuss if that will help but does it not mean to some extent going over old ground which has been considered already at Deputy Chief Engineer level and, that being so ought not any meeting necessary to be at considerably higher level to save having to go the rounds again?

Fantastic stuff. One day, two memos. Someone was doing overtime on that day!

Seriously, this does show just how bored of the whole question most of the Ministry had become, as well as quite possibly just how confused they'd all got themselves!

Final Approvals - November and December 1961

The policy for numbering motorways was adopted by the Highways Executive Committee on 23rd November 1961. The Committee recommendation was approved by the Minister on 16th December 1961.

The Committee had before it a note by Mr. Usborne proposing that a sector system should be adopted for the numbering of motorways. Mr Usborne explained that his proposal followed the principle of the sector system on which trunk and classified roads were already numbered, although the sectors themselves, which were six in number, were somewhat different. The numbering he proposed coincided with the present numbering of motorways in all except five comparatively small cases, none of which were motorways which had yet been started.

The Committee:

1. thought that the most important test was what the motorist would find most convenient,

2. noted that a change to the sector system at the present time would not involve any change in the system of numbering motorways which were now in use or under construction

3. agreed to recommend to the Minister that the sector system as proposed should be adopted.

And it's a glorious victory for the advocates of the sector system as you can see from the above memo.

It's a good thing that the National Archives have managed to keep hold of a map of this system too...

Map of final decided sectors


Part 5 - Running out of numbers >>

How the Motorways were Numbered


Part 1

Part 2

Part 3

Part 4

Part 5


Thanks to Jonathan Winkler, Chris Marshall and Mark Dillon for their help towards the production of this feature.