National Archives 2003-03-11
Arrived at Oxford railway station at 10.04, much as normal, and had little difficulty purchasing ticket/getting dose of railway cappuccino. Train ride to London very smooth and uneventful—in fact getting to London was far more boring than usual. Tried the Hammersmith to District Line trick this time, and found it worked much better than taking District whole way, and I got to Kew quite quickly. Had advance-ordered three files but took some back and got out others, so that a total of about nine files were looked at. It did not prove possible to do a full notetaking job on all, but files worth repeated looks were ID’d.
This file is described as containing “design policy on traffic signs.” In actuality it contains a great deal of correspondence between W Hadfield (the MOT civil servant having responsibility for traffic signs within the Traffic and Mechanical Engineering Branch within the Highways (Engineering) Division at the MOT) and various local authorities and road traffic sign makers. There is also correspondence to and from HE Aldington and AEN Taylor about the 1944 departmental c’ttee report on traffic signs. Reported coverage limits are 1946 to 1973, but the bulk of material comes from 1946-49 and although this file was scheduled for opening only in 2004, it received accelerated opening. Samples of issues covered include—
• Do local authorities have the right to impose tender specifications for traffic signs more restrictive than the MOT’s model specification for MOT-funded projects, especially when this causes certain makers to be prevented from tendering? Yes, they do, according to Hadfield, responding to a query from a maker which had been prevented from quoting because the LA wanted pressed aluminium signs and the maker would quote only on cast aluminium.
• Hadfield obtained a copy of the 1948 MUTCD and took notes on it. He also ran across what was probably Forbes’ first article on traffic sign lettering in PHRB, and took notes on it.
• How many signs on the roads are in fact authorized or otherwise compliant with specifications? Hadfield took a jaunt on the A41 and A34 (apparently an Aylesbury-Oxford-Reading one-day round trip) and came up with a catalogue (running to 4 pages) of unauthorized, non-standard, and other out-of-specification signs which should be removed. This was apparently done in connection with Parliamentary discourse (in 1948, reported in The Times) on the appalling state of British traffic signs. Times clippings included in file. || More details on this. Hadfield was apparently going to a conference in Stratford-upon-Avon and the four-page log of signing errors was compiled during his road trip there. He sent it to GH Hargreaves, the Divisional Road Engineer for the Metropolitan Division, with three pages setting out the general trends he saw in LA noncompliance. A member of Hargreaves’ staff sends a two-page reply indicating that they were aware of the nonconformities and that signing had been prioritised low in order to avoid diverting resources from carriageway repairs. A similar letter from the Divisional Road Engineer for the Eastern Division (apparently having jurisdiction over part of the area Hadfield travelled through) makes specific references to inadequate funding in the 1947-48 financial year.
We will reproduce a few extracts.
RTS.1 [for] Mr AEN Taylor
LEGIBILITY DISTANCES OF TRAFFIC SIGN WORDING.
The following is an epitome of a Report issued in 1939 about experiments conducted in U.S.A. with about 400 observers, regarding the distances at which people could read direction signs under various conditions.
The signs used in the tst comprised place names of six letter words, but in each case the names had one wrong letter so that the question of guessing at the name from its general outline was eliminated. It seems to me that this elimination is not entirely fair when applied to direction signs because the reader usually has some idea what name to look for and so help from the general form of the word is permissible.
Further, in the tests the observers were allowed as long as they desired to decide what th eletters were, i.e., it was not glance reading as might be applicable to traffic signs. The experimenters thought that glance reading would involve shorter distances but had at that time made no tests to prove this.
The letters used were of two forms, “wide” and “narrow.” The wide form agreed approximately with the open lettering recommended in the 1944 Signs Report; the narrow lettering was rather narrower than the “compressed” lettering recommended in the Report. Spacing between letters was carefully arranged in accord with a rather complicated code. It is sufficient to say here that the arrangement was not unduly contracted nor was the spacing specially wide.
The conclusion reached as the result of the test was that the relation between height of letter and legibility distance was practically linear. For the wide lettering the distance was approximately 50’ per inch of letter for people with normal eyesight under daylight conditions. For narrow letters the distance needs to be reduced by about 20%. For both forms of lettering the distance needs to be reduced by about 15% for night conditions, whether these be floodlight signs in lighted areas or reflectorized signs in dark areas.
The Report also points out that people whose eyesight is not up to normal standards are allowed to drive vehicles and that some allowance ought to be made for this, dependent on any test which might be applied in allowing vehicle driving licenses. For a license in Great Britain the applicant is required to state that he can read a motor number at a distance of 25 yards. This represents rather less than 25ft. per inch of letter but, of course, the letters do not form words and so the person reading is not helped by the general outline.
The full report regarding the American tests may be found on pages 321-35 of the Proceedings of the American Highway Research Board, 1939, a copy of which is in the MOT library.
As the result of a personal test one lunch time recently, I decided that with open lettering a person with reasonably good eyesight would be able to read a word at a distance of 60 ft. per inch of letter in the extreme, with clear letters and adequate spacing. With poorer letter forms, etc., the distance in my case was never less than 52-55 ft. per inch of letter. I suggest that a distance of 50ft. per inch of letter for open lettering under daylight conditions might be quoted in any correspondence, with reducations of about 20% for compressed lettering and 15% for night conditions.
Mr JFA Baker Devonshire House
Drawings of Traffic Signs Lettering.
You will, no doubt, be aware that a standard form of lettering has been agreed for all traffic signs.
At the present time many drawings of signs are being lettered by hand rather than by the use of stencils and naturally, the precise form of recommended lettering is not always followed.
It would be a great help in this matter if suitable stencils could be used. It is understood that the recommended lettering necessitates special form of stencils, i.e., not the standard “UNO” ones. It is also understood that Establishment Division (Mr. Ray) has the matter in hand, but it would be appreciated if you could help by expediting the procurement and use of such stencils.
(signed) W Hadfield
Traffic and Mechanical Engineering Branch Highways (Engineering) Division Berkeley Square House 21st May, 1946
Further file content notations:
• Drawings in envelope at back: these are large-scale drawings of “TRAM PINCH” (worded part only, pre-Worboys), “RIGHT” on plate (partial plate only, also pre-Worboys), and the bend symbol on the winding road sign (also pre-Worboys). None worth P.
• Letter to AEN Taylor from a traffic signal vendor in Manchester—“have you seen the 1948 MUTCD”? AEN Taylor asks Hadfield with pen note on letter (Hadfield apparently Taylor’s junior), does he have a copy of the 1948 issue—Taylor’s own copy is old and well out of date.
• Report, dated 11 April 1949, of Hadfield’s visit to the Royal Label Factory, a traffic sign maker in Stratford-upon-Avon. It was during this visit that Hadfield noted all the noncompliances in his route log. Extract perhaps worth reproducing.
Royal Label Factory
I visited the Royal Label Factory on 8th April and report as follows
The business is an old family one, primarily devoted at the present time to aluminium casting though occasionally they do cast other non-ferrous metals. The pamphlet attached, which has bjust been prepared in connection with a local exhibition, gives a brief history.
From what I saw I estimate the number of employees at present as between 30 and 50 and the work now being done is MOT signs, loose numbers and combination numbers for houses, grave markers, and a miscellany of artistic type signs, office labels, etc.
Patterns for MOT signs are either complete in themselves, for signs commonly used, or, as in the case of direction signs, comprise back plates on which loose letters and numbers are fixed. The fixing is done by coating the back plate with a molten wax, keeping this hot while the letters are put into position, and then cooling it off so that the wax sets and holds them. The positioning of the letters is checked by callipers so that the standard of setting out is fairly high.
All moulding is apparently done with sand. The largest moulding box was about 6 ft by 6 ft. The two halves of this box are hinged along one side and a crane is used to raise and lower the upper part. This is the box they use on the large area direction signs and they get extremely good results, the plates being very true and flat, although only about ¼” thick. The firm’s engineer explained that the most important thing in getting such castings is making sure the metal runs properly and having adequate weight holding the mold together.
The metal used is usually a 6% silicon aluminium but they do sometimes use other aluminium alloys and some other metals.
The castings are at present fettled by hand but when I asked about this I was informed that in the last week they had inspected a new machine in Birmingham which they think will help with this work and they are considering the possibility of installing one.
The firm have also just installed a shot blasting apparatus, but the installation was not quite finished.
The colouring is done with a synthetic enamel and the firm claimed that they have had appreciable discussions with the paint makers about the best enamels and now are well satisfied with the products they have been obtaining from this paint firm for several years. The enamel is applied by hand with brush and the signs subsequently stoved in a gas oven. I asked about application by roller, but with the cast surfaces the roller apparently leaves gaps which have subsequently to be touched up and, in the firm’s experience, there would seem to be little advantage in using a roller with cast surfaces.
I was a little bit pushed for time and am afraid I did not see the fitting of reflectors. We know, of course, that it is done by cementing them in position and the reflectors are obtained from Messrs. Spear and Edwards, Darton, Yorks.
11th April 1949
VARIOUS COMMENTS ABOUT TRAFFIC CONTROL IN U.S.A. BY SIGNS AND SIGNALS REFERRED TO IN “TRAFFIC ENGINEERING” DATED FEBRUARY, 1949.
At some few difficult cross roads “Stop” signs (equivalent to British “halt” signs) are inserted in all four roads. It has been found desirable to indicate this on the actual signs by additional wording. The Americans had “4-Way.” Apparently this is at present confined to a very few junctions and it would seem desirable that it should remain so. The report suggests the following criteria as justification with present limited knowledge.
1 400-750 vehicles per hour for 6 hours with a ratio 60%-40% in Urban areas. 300-750 vehicles per hour for 6 hours with a ratio 65-35% for Rural areas. 2 Accident record under two-way control, i.e. normal “Halt” signs. 5 right-angle accidents per year resulting in property damage not less than $50 or 3 personal injury accidents, in Urban areas. 4 similar damage accidents or 2 personal injury accidents in Rural areas. The report shows beneficial results obtained at two junctions. The best example is one where in 1938-42 14 accidents occurred resulting in 3 deaths and 40 injuries under “two-Way” control. From 1942 to the present time only 4 accidents occurred with no fatalities and 3 injuries under “four-Way” control
Most long-distance drivers travel by road numbers. Confirmatory markers are frequent. In Virginia, the route number is painted on the back of all warning signs. “Note: these will be on the off side of the road.) This latter is an idea we might consider extending to Great Britain.
The yellow light signal is a traffic menace, which means whatever the driver wants it to mean. To taxi cab drivers it means “Go”; to others it means “Keep Going”; to yet others “Stop if you cfan.” Where it has been replaced by an overlapping of the red, traffic is better controlled.
Some of the most ineffective directions to road traffic are those painted on the highway itself. Those who are responsible for such signs indicate no knowledge of the principles of perspective. A letter four feet high and two feet wide (similar to British “SLOW”) would appear to be 2 ½ inches high and 2 feet wide to a driver 200 feet away whose eye is 5 feet above the road and this is not readable. If a letter painted on the road is to appear as high as it is wide to the driver at 200 feet distance, the actual height should be 40 times the width of the bottom of the letter and the top of the letter 20 per cent wider than thebottom. The writer also makes reference to vehicles ahead covering these signs.
New York has just los a Court action, incolving $68,000, in which 2 deaths occurred and in which it was alleged the warning signs did not conform to the Federal Manual. The case is on appeal.
Two machines, one supplied by Prismo and the other by Minnesota Mining and Manufacturing, gave widely different results in measurements of the reflectivity of beaded reflectors.
[date ripped off, but no doubt 1949 sometime—23rd of some month]
Some questions about Mr Hadfield:
• Is he the Hadfield to whom we owe double yellow lines?
• Is he the Hadfield (or Hatfield?) who wrote a book on the history of highway construction—the British answer to LI Hewes?
This contains a very rough draft of TSRGD 1964 together with a very modest amount of added material—a sheet dated 20/4/1964 which counts the diagrams (comes up with about 550 total) and comments on the draft itself. The draft consists of many sheets of paper which have figures from the Worboys and Anderson reports rubber-cemented to them, and occasionally conceptual drawings of alternative designs which the Ministry wanted inserted into Regulations. Many of the Anderson, and a few of the Worboys, direction sign designs were crossed out in ballpoint, and accompanied with instructions—usually either “OMIT” or (in the case of the Anderson-style curved fork signs) “redesign per [Worboys drawing number].” Many of the signs proposed in the Anderson report bit the dust at this stage. These included the fork signs, which were redesigned to use the same straight-arm fork signs recommended in the Worboys report for access-controlled, motorway-standard dual carriageways, albeit with certain variations—such as the motorway route number being allowed to be level with the outward-pointing arm, rather than above it—and also the “motorways diverge” fork sign developed for the M1/M45 interchange, which was “not to be prescribed,” and the special overhead signs recommended in the Anderson report for cloverleaves (“not to be prescribed” also, but using the same signification concept for the downward-pointing arrows as for contemporary American Interstate signs—the same design concept that was heavily criticized in Congressional hearings in 1968-73), and the alternative design for overhead sign with downward-pointing lane arrows which did not use the horizontal line between the arrows and the legend (also to be omitted). (This latter omission was restored in the 1975 regulations.)
Other Anderson sign designs were heavily modified. “Services” in so many miles was modified to cite the name of the services (“Forton” penned in on the drawing cut-and-pasted from the Anderson report), all flag signs having pointed ends were redesigned to conform with the Worboys-style chevron end, all signs using the stub arm with 60° end were redesigned to use thicker stub arms with 90° ends, all signs using the Anderson filled-barb arrow were redesigned to use the Worboys-style right-angle arrow, the Motorway Standard alphabet was required to be tiled. Comments demanded that some of the important Anderson examples (e.g., “M1 Birmingham”) be modified so to require that Birmingham either be enclosed in brackets when used on signs referring to the M1, or that a different destination (one actually reached by following the M1) be used.
This file does not contain the actual designs which were generated as a result of the modifications demanded, but it nevertheless provides definite documentary evidence that the MOT required that the Anderson motorway signs be redesigned to conform to the same stylistic scheme as the Worboys signs before they, like the Worboys signs themselves, were prescribed.
There is also an interesting example: for one primary-route map-type direction sign (cut and pasted from the Worboys report) for a roundabout where one of the arms leads to a motorway which in turn leads to another motorway—“St Albans M1 (M10)” or similar—the commentors wanted the legend pertaining to that arm to appear on a WoBl patch. Was this in fact done? I don’t think so.
Physically this file is not in excellent shape. The rubber cement has dried out and lost its adhesive power, so many of the cuttings are no longer securely attached to the page, and in fact several are floating around loosely in the file.
It was identified as being required to be closed until 1994.
The commentors whose pen-and-ink comments appear on the draft Regulations are apparently anonymous in the sense that their full names are nowhere given. However, many of the comments have the initials “TS/WP,” or “TS” alone, or “WP” alone. These appear to be people’s initials rather than acronyms for terms like “traffic sign” etc. It is not altogether clear whether TS and/or WP (assuming they are real people) are acting on their own administrative authority in demanding the changes to the Worboys and Anderson proposed figures, or if they have been appointed to express an administrative consensus agreed by others (possibly their superiors).
There’s not much happening in this file. It dates from 1959-63, was closed until 1994. Contains correspondence with the London County Council with respect to a map of radial trunk roads (including motorways) emanating out of London which they wished to include in a publication, and also a map of proposed motorways which the Min of Housing and Local Govt wanted for a map of post-war developments (in transport, housing, coal, railway electrification etc.) they wished to publish. Both maps are enclosed. There is some, but not much, interstitial correspondence.
There are also a number of “Engineering Appreciations” for trunk roads. These refer to the trunk roads by a trunk route designation number, which appears to be the number in which such roads are listed in the Schedule of trunk roads in the 1946 Trunk Roads Act. These numbers are probably no longer in use:
• HGP 18/3/03. Trunk road master plan. Trunk road No. 3. London-Great Yarmouth Road. Metropolitan and Eastern Divisions Engineering Appreciation. July 1961.
• HGP 18/33/03. Trunk road master plan. Trunk road no. 33. London-Tilbury Road. Metropolitan Division Engineering Appreciation. June 1961.
Also, an interesting article from the Banbury Guardian, 10/8/1961:
Planners want new Midlands-South route
Motorway may skirt Banbury
To replace town by-pass?
A new motorway punched through the countryside west of Banbury to link the Midlands with the south Coast is being considered by the Ministry of Transport.
It would replace the proposed Banbury by-pass for traffic between Oxford and the Cdoventry-Birmingham area.
Mr. Ernest Marples, Minister of Transport, is not ready to put the scheme forward officially. But its existence has leaked from Whitehall.
The new motorway is planned to start near Southampton. It skirts Winchester and the Newbury bottleneck to link up with the Oxford by-passes.
The route northwards has not been decided in detail.
But the motorway would probably pass to the west of Banbury in the South Newington-Bloxham vicinity before crossing the Banbury-Shipston road. It would then carry on the Kineton and Gaydon area heading towards Coventry.
Links with Banbury are planned for the new road. One would probably use the Warwick Road, another the Bloxham road.
Other roads westwards from Banbury would go over or under the motorway.
One aim of the motorway is to divert heavy through traffic from Oxford to Coventry away from Banbury. Other lorries now using the A41 could also travel on the new route.
With ever-increasing industrial and population expansion in Banbury and North Oxfordshire, Ministry experts have pointed out that additional road capacity would be needed.
And the big motor firms who have been forced to expand in Lancashire and Scotland are also expected to make heavy use of roads in the area for transporting bodies and components.
Local authorities through whose areas the motorway would pass are expected to be consulted between now and the end of the year.
The spider of motorways already under construction, or decided on, has one vital leg missing—from the Midlands to the South, avoiding London.
It is this leg that Ministry planners want approved—and which, it is hoped, will rid the present Oxford-Banbury road of its “killer” reputation.
[Article is accompanied with a map which shows the proposed new motorway as a dotted line, starting in Soton and passing Winchester (E), Newbury (E), Oxford (W), Chipping Norton (E), Banbury (W), Warwick (W), and Coventry (W) before hooking up with a motorway N of Coventry which has spurs to Yorkshire and goes on to B’ham and Lancashire.]
Plus, there are also summaries of what is shown on the MHLG map (obviously prepared by the MLG—it’s a 1:625k map, apparently, and a “position of motorway construction as of . . .” table dated 1st April 1959. First 60 miles of so of M1 shown as being in progress, along with Ross Spur, Maidenhead and Slough bypasses, Lancaster by-pass, and 30 miles of M5. Only completed scheme is Preston By-Pass.
This file contains the RRL’s own copies of the research reports commissioned by the Anderson committee (CTS series). The papers and their CTS numbers and titles are as follows (page numbers in parentheses):
1 A preliminary experiment on the daylight legibility of signs with different color combinations for legend and background. (3) 2 Notes on a demonstration of signs: Hendown, 24th April, 1958. (5) Includes pattern-accurate diagram of the sign which was used at Hendon—it is the same as the American-looking one included in MT 113/48. 3 Observations made on the experimental signs at Hendon. (4) Includes photograph of the signs on their test rigs. 4 A note on some recent American sign tests. (2) This is a summary of a BPR/AASHO test of sign backgrounds carried out in 1957 when Interstate signs were being designed. It deals with preferences for backgrounds—reflectorized preferred even though painted black background offered superior legibility. 5 Notes on a demonstration of signs: Hendon, 18th August, 1958. (1) Main objective of this experiment was to allow UC/LC and different color backgrounds to be viewed in the field. Night viewing apparently simulated by putting the signs in a shed. 4 in MOT UC compared with 3 ½ in loop height LC (apparently the Kinneir font). 6 A note on recommendations for signs for Italian autostrade. (3) Quotes Le Strade 1958 38 (5) 185-192 on an Italian committee’s recommendations for signing motor roads. Includes 2 illustrations from the article, and observation that Italians are using all-UC. 7 Measurements of legibility distance made on the experimental signs on the Prston By-Pass. (2) 8 A note on an experiment with direction signs of types used in America and Europe. (3) Includes drawings of the signs used in the Slough experiment. 9 [There is apparently no CTS 9] 10 Optimum letter size for a sign of given size. (3) Deals with how to arrange letters on a “POLICE STOP” sign, which has to be of fixed area so it can be carried in patrol vehicles, to optimise legibility. It carries forward earlier work by Solomon (the 1956 sign study) and Bridgman and Wade. Conclusions of them are summarized as follows: Solomon says that for signs bearing reflectorized legend at night (Series E letters), legibility distance could be increased 15% by increasing spacing between letters so that word length is 40% greater than normal, but by using the increased area of sign to accommodate larger letters at normal spacing, legibility distance could be increased by 25%. (This was more or less confirmed by the RRL research described in this paper.) Bridgman and Wade (JAP, 40, 6, 378-380) recommend that letters should be made as large as possible—up to the point of very nearly filling the available space (margin less than the stroke width of the letters), in order to permit descrimination at a maximum distance.” 11 Relative legibility distances for signs with upper and lower case lettering. (2) This is the Kinneir/Kindersley comparo. Interesting quote: “In America it was found that the legibility distance for single-name lower case signs was 10% greater than that for similar upper case signs when the lower case X-height equalled the height of the upper case letters. Unfortunately the application of these result to multi-name signs is questionable.” The conclusions: (1) Where ample interlinear spaces and margins may be allowed there appears to be little to choose between good upper and lower case sans-serif alphabets; (2) where the aim is to get the maximum legibility distance from a sign of given area there is strong evidence that an upper case alphabet is to be preferred to a lower case alphabet; and (3) experimental results have been obtained which cst doubts on the value of serifs on upper case letters when legibility distance is assessed relative to the area occupied by the letters. 12 The choice of colors for emergency signs for use on motorways. (3) 13 The alignment of motorway direction signs. (4) lThis dels with the best way to avoid specular glare.
This file contains all the documentation attaching to the RRL side in a controversy over frost damage on the Preston By-Pass, which raged through 1959 and eventually affected the London-Birmingham motorway as well. The principal protagonists were Dr William Glanville (DRR), two functionaries at DSIR—BK Blount and Learmouth—who appear to have been senior to Glanville, someone called the “Lord President” who appears to have been head of DSIR since his rank was evidently parallel to Mr. Watkinson’s as MinT, and JFA Baker, the Ministry’s Chief Highway Engineer, and LJ Dunnett, the Ministry’s PS. Documentation includes:
• The RRL’s preliminary report (not numbered in the RN series) on the causes of the frost damage on the Preston BP.
• The RRL’s full report into the causes of the frost damage, numbered as an RN.
• The RRL’s report on transverse trench excavations in the PBP, designed to elucidate how the lower layers failed. There appear also to be preliminary and full versions of this, both numbered as RNs.
From the RRL perspective, “what happened” is broadly on these lines:
Initial discussions over the design of the Preston By-Pass (PBP) between the Ministry and Lancs CC (Drake) took place in 1954-55, before the scheme had been authorized to proceed. Thereafter there was no detailed ministry oversight over the PBP design, with the Divisional Road Engineer for the North West apparently rubber-stamping the required approvals. Although the RRL had consulted in the development of new construction specifications in 1957, PBP was designed and constructed to earlier specifications which had not been generated after RRL consultation. RRL in general, prior to this controversy, was not being consulted on schemes until very late in the day (same time as the SMMT in one example cited by Dr Glanville). Further, the actual construction depth over much of the PBP was less than specified in the contract. Meanwhile, the RRL had carried out tests at Alconbury Hill (prior to the design of the 1957 specifications? If so, why didn’t 1957 specs emphasize drainage as well as choice of impervious materials?) which emphasized the importance of good drainage.
Then the whole frost heave event happened.
RRL (Glanville and Maclean) and Ministry (JFA Baker) immediately went up to inspect—at this point Lancs Co Police had closed the entire road, although the frost heaving affected only 1% of the surface. Reason was that they were not sure how much worse the problem was likely to get, and as the road was meant for high-speed travel, any defects in its surface were correspondingly more harmful to traffic safety. The RRL’s initial conclusion was that the wet-mix limestone layer used in the PBP was excessively susceptible to frost and should never have been used without an impervious layer above it. Furthermore, some preliminary digging showed water trying to squeeze out of the pavement layers—a sign that edge drains should have been provided for in the design, but were not. (The chairman of the Lancs CC, trying to defend Drake, was quoted in a Blackburn newspaper as saying that Drake had wanted to put in edge drains but the Ministry said No. Watkinson was grilled in Hansard over this—pp. 1070 et seqq., don’t remember specific date, but in 1959—but said smoothly that the chmn had said he had been misquoted in later edns.) JFA Baker, trying to pull off a CYA number, gave the reasons for the failure and then implied that it could not have been avoided because the road had been built to specifications reviewed by the RRL. This drew major anger from Dr Glanville, who wrote letters to his seniors and the Lord President, etc. pointing out the true facts as listed above, and who replied in sharpest terms to Baker. This correspondence not only played up the failure to provide for adequate drainage (ie to make best use of the RRL’s Alconbury research), but also other design errors at Preston, such as the failure to provide an impervious wearing layer, the failure to build edge drains for the pervious layers, etc.—all problems advised against in the RRL’s existing Road Note publications (12, 17, and 20 cited specifically).
Lord President intervened by asking Glanville to write biweekly reports while the RRL’s investigation into the bypass failure was in progress. (Glanville complied, but these reports were not in fact shown to the LP, as they were felt to be too technical. Senior DSIR personnel conspired in hiding this fact from Glanville.) Also, a meeting was called between Watkinson, Glanville, and senior MOT personnel. (DSIR HQ staff not invited, and they groused about it.) It was generally agreed that both RRL and MOT wanted to see best use made of research results, but a concordat had to be negotiated, whereby RRL would be consulted on design at early stages, and (this implied) in no case be blamed unfairly for problems with schemes where it had not been invited to consult.
Concordat kicked into effect and forced the RRL to be involved in pavement design for the London-Birmingham Motorway (LBM). Much of the LBM was apparently to be built of “concrete” (I take this to mean PCCP) yet was to be haunched under the nearside, which Glanville feared would cause differential stresses across the pavement surface and lead to the breaking-up of the concrete. Meanwhile, a flexible design was also under consideration for the LBM—it is not clear whether this was a flexible alternative to the rigid pavement about whose “haunching” Glanville had protested, or if both flexible and rigid were being used on different stretches of the same general length of LBM. In any case, Glanville was concerned about the bearing strength of the lean concrete proposed for one of the underlayer, and insisted (MOT complied) on the 2 in top wearing course being doubled in thickness over the entire length to minimize the risk of water intrusion. Glanville’s concerns about the lean concrete arose from his belief that the engineers should design for 1000 lb/sqin minimum rather than 500 lb/sqin minimum and that, although the existing lean concrete design could deliver strengths ranging between 500 and 1000 lb/sqin on the assumed CBR of 4, there appeared to be stretches of the road where the actual CBR appeared to be less than that by considerable amounts. The MOT made much of its willingness to double the wearing course thickness as a sort of concession, as apparently many of the sections supposed to be receiving flexible construction were already being built. Baker not overfond of Glanville’s idea to build for 1000 lb/sqin minimum because he feels this will compromise the flexibility of the road excessively. (Query—what’s the design advantage of flexibility? Does it exist or is Baker just blowing smoke?) (Consultants designing LBM = Sir Owen Williams and Partners. Glanville writes direct to OW about the concrete haunching issue. The lean concrete issue is thrashed out at Ministry level—ISTR Dunnett was present, but need to check.)
This file is FULL of photocopiable material and will have to be returned to again and again as thesis is being written.
NB: at the plenary meeting Glanville was asked about the proposal to take the RRL under the MOT, something that had been floated in 1954 or so. (See Charlesworth for the details—and pray he isn’t being a fuddy-duddy again.) He said he thought that, on balance, the advantages of independence outweighed the disadvantages.
This is one of the files on the Birmingham-Preston Motorway—contains:
• Petitions, including many from villagers in Leyland who will be affected by the Leyland Link Road and the traffic concentrations it will bring, against the scheme. (Not altogether sure whether these petitions object to the original scheme or to the first variation.)
• Copies of the statutory instruments for the scheme and its variation.
• 16 six-inch ordnance survey maps (accompanying scheme and variation) indicating location of the proposed new road and its slips.
• Letters from objectors.
• Internal ministry correspondence—let’s change this to a roundabout to answer this group of objectors; no, let’s change it back to the original design (and remove it from the Variation) because this group of objectors is louder and more vocal; etc.
• Letters from local authorities regarding scheme & variation.
• Copies of form SR.1, to be sent to the Chief Highway Engineer when the Divisional Road Engineer recommends that a special road scheme be Made. There are about 4 or 5 of these, apparently pertaining to different segments.
This material all originates from the conceptual stage—no preliminary design, no final design, just administrative correspondence (apparently) about the enabling line & slip road orders.
This is the file on Contract No. 2 for the Chiswick-Langley flyover, AKA the Boston Manor bridge contract. Part of the bridge called for concrete, while another part called for steel. The steel part seems to have caused a lot of trouble. I don’t understand the technical stuff about welding, but apparently Sir Alexander Gibb and Partners (the consultants) designed around steel complying with BS 896:1941 while a sub wanted to build it better and cheaper using steel to BS 896:1961 (the difference between the two not quite specified, but apparently the 1961 steel is high-strength, while the 1941 is ordinary, or something like that), and got MOT to force the Contractor to take on that sub and to accept that sub’s design concept. Meanwhile, because 1941 steel not quite the same as 1961 steel, consultant forced to redevelop parts of the design. This leads to delay, not covered by change orders (the contractor eventually applies for £453,000 additional when the total of change orders approved by Gibb & Partners runs up to £53,000). To their credit, Gibb kicked up a fuss about this (not sure whether before the tenderer with 1961 steel was accepted, or if being “wise after the fact” as RRL was initially accused after PBP pavement failures)—they mentioned the delay, the added costs, and suggested that contractors should be required to bid for 2 and 4 month earlier completion times and state what additional facilities (such as lane closures on nearby major roads) they would need. Nevertheless, there is a complicated adjudication process at settling-up time. Also, complaints heard from the RRL (Glanville) to the effect that running the pavement across expansion joints is asking for trouble—the pavement may break up because the steel plate spanning the joint is not stable. But the alternative, exposed expansion joints with “saw cuts” in the road surface (?) has ride quality problems of its own. Further complaints are also heard about the gantry signs. Problems apparently caused in the early to mid 1960’s, apparently after completion of the viaduct, with overheight trucks getting on the motorway and hitting the steel gantry. One of these, a truck carrying a crane, had a crane part get caught on the gantry, where it tore off a metal part which subsequently fell into the nearside lane—fortunately no-one killed or injured. Height bars with bells on the entry slips proposed as a fix to this problem. London boro of Hounslow writes to Ministry in 1965 to complain about how unsafe this is. File started 1958, consigned to archives about 1965-66, closed until 1998.
No plans in this file, except very partial details for the steel and concrete parts of the viaduct, and a single photograph showing a Barber-Greene paving machine laying what appears to be RC.
File has interesting material, maybe relevant, not to be returned to soon.
A more detailed summary to be written at leisure. This is about a Motorways Working Party and its Traffic Engineering [sub] Committee. Many design issues covered; WP included AA representation and was intended to be a “lessons learned” board for the LBM. Very interesting info on relative casualty rates on the LBM, and how affected by winter opening and fog.
File is definitely worth going through another time, but in meantime will attempt a précis of contents from memory.
Motorway Working Party was convened to examine a variety of issues arising from the LBM. These included:
• Whether to provide stabilized vegetated (grass) or fully paved hard shoulders. (The typical stabilized vegetated HS appears to have been turf in sand on top of lean concrete. It was considered problematic because it was difficult for drivers to tell the verge, which had no reinforcement, apart from the HS, which was designed to take vehicles. Edge marker posts were to help them with this task but the prevailing spacing of 110 yards was believed too high. HGVs were not using the HS because they couldn’t be sure they wouldn’t get bogged down in it. Initial HS recommendation, in the 1947 standards which were not actually used to build any motorways, were for 4’ 6” HS, which was not nearly wide enough to allow vehicles to pull completely off the travel lanes. 8’ hard shoulders were provided on the LBM—and at the PBP?—but there was an additional problem; before the vegetation got properly established the HS were slick and boggy, and it was easy for vehicles to overrun the reinforced part and get their L wheels stuck in the verge. Although OW verbalized indifference as to whether vegetated or paved HS were eventually adopted, and pointed out that it would cost around £500,000 to add a full paved HS over the whole length then open of the LBM, C’ttee consensus was shifting very heavily toward paved. Eventually, by the time the LBM had been open for some length of time—a year?—80% of its length had been retrofitted with a paved HS, with the remainder to be retrofitted after the winter was over. Check this.)
• How serious was the problem of spray during rainstorms? What causes it, possible mitigations, etc. (There were about 2 RRL research reports—RNs?—on this. One was a laboratory experiment where a test vehicle was driven into a splashing pool of defined water depth at varying speeds to photograph and measure the water jets emanating from the pool at given speeds. The objective was to understand the physics of water splashing given an idealization of the hydrodynamic characteristics of vehicle tires, Bernoulli’s law, and assumption of streamline flow.)
• Refinements of carriageway markings to enable exit slip roads to be more easily located—file includes a typical drawing of the two-headed arrow slip road marking.
• Refinements to the signing system. (The Third Report of the Traffic Engineering Committee, created as a subcommittee of the Working Party to consider traffic signing issues, is especially useful in this regard. The AA representative—Greig?—name sounds familiar; maybe he dates from RJ’s time—and also one of the MOT’s traffic engineers, specifically CH Wykes, was to be on this committee.) The committee recommended eliminating “GET IN LANE” from the 1-mile ADS for the M1/M45 split, since it was not clear at that point which lanes went with the M1 and which went with M45. In general suggested getting rid of “GET IN LANE” injunctions except at locations where it was very clear which lane to get into.
• Early traffic safety indications on the LBM. Its performance was assessed after it had been open a few months (spring 1960—March?—need to check and verify) and was felt to be dismal. It had 0.11 fatalities per million vehicle miles, which was about five times greater than the NJTP’s average of 0.020 fatalities/MVM, and about 3 times greater than the US freeway average of about 0.035. However, there were just five fatalities—a very small sample—and the motorway had at that point been open only during the more heavily precipitated winter months, in a year where the fog had been unusually heavy. Traffic had not yet had time to be acclimatized (the TEC pointed to a reduction in fatality rate on the Penn TP between 1940, when it opened, and 1956, when the last figures were available, and it was dramatic, ‘tho can’t remember the specific figures—think the Penn TP’s 1940 fatality rate was higher than the LBM’s initial).
• Dazzle fences? This was tried on a test section of the LBM. Opinions mixed as to its value. They minimized glare, but also encouraged drivers to put on their main beams all the time instead of being responsible and dipping their headlights.
• Much active debate over whether motorways should be lighted, and calls made for a demonstration project to determine feasibility and benefits of lighting. Nothing seems to have gotten off the ground under this c’ttee (first lighting experiments not tried until much later).
• Inconsistent use of roadworks signs on the motorways—C’ttee felt that a code of practice needed to be introduced urgently and more zealously enforced by MOT personnel responsible for supervising roadworks.