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Activities involved in building the Motorways

Legal Background

The provision of the Southwest’s Motorway network has been promoted by the National Government which it was empowered to do by legislation, firstly under the Special Roads Act 1949, and then the Highways Act 1959 into which the earlier act was incorporated. This legislation required the publication of separate Schemes showing proposals for the main line of the Road, for rights of way effected by the main line (ie. roads, bridleways and footpaths crossing the line and slip roads joining the main line to the existing road network. Notices were published in local newspapers stating where plans could be seen in the local area. After a period of thirteen weeks during which time any person aggrieved by a scheme could lodge objection the Minister had to decide whether it was necessary to hold a Public Inquiry before an independent inspector. On receipt of an Inspector’s report the Minister would then decide whether to confirm, modify or abandon the scheme and publish new proposals. The final decision of the Minister was published as a Statutory Instrument.

It will be seen that the Minister had two roles in the Motorway Programme, one was the promoter of the proposals in the National interest and the other, quasi-judicial role, was that of decision maker under legislation which could be the subject of legal challenge in the High Court. In order to separate these two conflicting interests in the early days of the Motorway Programme the Ministry of Transport had separate teams, one dealing with the Engineering and the proposals the other, the administrative side, dealt with any public inquiry and recommended decisions to Ministers.

To achieve the legality of the line of the M5 Motorway from Ross Spur to Pearce’s Hill twenty two Statutory Schemes and orders were published between 1964 and 1973 and seven public Inquiries were held :-

  • Easton-in-Gordano to Clapton Wick section (Side Roads Order only) May 1969
  • Strensham to Brookthorpe Section (Supplemental Side Roads Order only) June 1969
  • Edithmead to Huntworth Section (Line and Side Roads Order) July 1970
  • Huntworth to Willand Section (Line and one of the Side Roads Orders) September 1970
  • South of Cullompton to Poltimore Section (Line and Side Roads Order) July 1971
  • Poltimore to Sandy Gate Section ( Line and Side Roads Order ) July 1972
  • Sandy Gate to Pearce’s Hill Section ( Line and Side Roads Order) February 1973

On the M4 it has been impossible to establish exactly how many schemes were published on the length between Tormarton and Membury, nor is information about Public Inquiries available. It might appear from the details and from the phraseology in the opening brochure that no inquiries were held because of the extensive work undertaken to find a suitable route between Swindon and Holyport, however this is highly unlikely. Draft schemes were published between 1966 and 1968 and Statutory Instruments finally settling the route were made in August 1968. The section of M4 from Almondsbury to Tormarton was the subject of a Public Inquiry in August 1962 and this is referred to later in this report.

The incidence of public inquiries on these schemes is of interest. The design and administrative phases of the early sections of Motorways, in the 1950’s, were developed and went forward though the Statutory requirements almost without objection and where there were objections modifications were somtimes made to accommodate them. However the later schemes, at the south end of the M5, required Inquires which were jointly into Line and Side road orders. The reason for this is considered to be twofold. As more lengths of motorway opened so public objection became more sophisticated and so the "NIMBY" (Not in my back yard) syndrome developed hence separate Inquiries offered greater chance for continued objection and thus delay. Also the new RCU was planning to firm timetables which needed clarity of purpose so it was highly desirable to develop a scheme in consultation with the public in an area and then face issues in total at a public inquiry. However the detailed information required to face almost mandatory inquiries also grew as the programme developed.

The legal process for the two Severn Bridges required special Parliamentary Bills as both bridges were over navigable waters. In the case of the second crossing all the amendments to the Motorways M4 and M5 and the new sections of Motorway M4 and M48 were included in the Bills as well as proposals for re-establishing and establishing tolls on the two Bridges. The Bill was approved in principal after two readings in the House of Commons and a select committee sat for ten days considering objections. A much simpler process than some of the extended inquiries under the Highways Act.

Public Inquiry into the M4 Tormarton to Almonsbury

It is fortunate that a copy of the report of the Inspector into the line and side orders for this length of the M4 is available to the Archive and can be examined in some detail. It is a sign of the importance attached to the scheme that the representative of the Ministry was J.G. Smith the Deputy Chief Engineer. Mr. Smith was both Principal Witness and Advocate which was the practice in the early days of Motorway Inquiries. Later on in the 1960’s Assistant Chief Engineers were appearing at the major inquiries and by the 1970’s Superintending Engineers in the RCU’s were the main Ministry Representatives. It is believed that when Parliament laid down legislation for such Inquiries they were not intended to be intimidating court room proceedings but, as the name implies, inquiries so that persons affected could question the proposals before an independent Inspector whose report would help the Minister to his final decision. This particular Inquiry shows the style of the early motorway inquiries with some people represented by Solicitors others by Chartered Surveyors and a group by a Counsel together with a number of people speaking for themselves. The proceedings are well recorded and well summed up by the Inspector : it reveals how, although the proposed line of the road had been protected from development by the inclusion in the Gloucestershire County Development Plan (which had been supported by all the Local Authorities) the route had, over time, become the limit of development with houses built and sold adjacent to the boundary of the proposed motorway. As the countryside beyond the route was undeveloped the natural reaction from persons in houses close to the route was to demand it be moved further away notwithstanding the property had been bought in the full knowledge that a major road was proposed adjacent to it. The strategy of Counsel is also somewhat typical; seeking to argue the case was broadly a Town and Country Planning issue which needed the presence of the County Planning Officer. In the subsequent report the Inspector, supported the objectors and recommended the line be moved. The Minister accepted this view and the route was subject to modification with consequent delay to the scheme.

Information required for the Design of a Motorway

In order to produce a practical and effective design, which can be fully justified at any Inquiry and to enable the compulsory acquisition of land, considerable information is required. Gathering the information on a series of possible alternative routes requires the mounting of various detailed surveys as follows:-

  • Traffic surveys - to determine the best traffic solution, the location of interchanges and the benefits of a scheme.
  • Topographical surveys - to produce details of the ground shape to enable the design of earthworks, the location of bridges and minimize environmental damage.
  • Land Use and Property Surveys - to minimize effects on property and to determine the works required to avoid disruption to property & sites of special scientific interest etc.
  • Soil and Geological Surveys - to determine the nature of strata and the foundation conditions for structures, the earthworks and the highway.

In the early 1960’s computers were in their infancy so all the information required was collected and processed mainly using maps and manual methods. Hence the preliminary design work to achieve sufficient information to make comparisons between alternatives was laborious and time consuming. At a later stage Air Survey techniques were used for topographical work with ground control to fix mapping. Now modern techniques using computerised equipment and satellite technology have transformed all the manual methods.

Route Location

In order to achieve a "free flowing" alignment which ensures good forward visibility for vehicles on the road and to avoid steep gradients which cause congestion due to slow moving traffic the Ministry had laid down minimum standards for motorway design. These required the normal minimum curvature to be of a radius 5730 feet (a one degree curve) with the absolute minimum radius of 2865 feet and a normal minimum gradient of 3% or one foot rise in thirty three feet. If possible these standards should be the lowest and generally the route should fit well into the landscape following the grain of the land and avoiding where ever possible cutting at right angles through escarpments with resultant "Vee notch" effects.

On the M4 Motorway the location of the crossing of the River Severn Estuary dictated the western end of the route in the vicinity of Bristol and the need to provide access to the Motorway from Bristol dictated the route should be as close possible to the northern limits of the conurbation. Further east it was necessary to ascend the Cotswold Escarpment and to avoid the area of Dyrham Park (National Trust) so the natural location for the Interchange with Trunk Road A46 was in the vicinity of Tormarton. Further to the east the presence of the towns of Swindon and Reading were two crucial factors in route location. It is apparent from an examination of the route that it should pass near to the Swindon which was then a major traffic generator (and is now even more so ).

The location in the Reading area was more complex. In order to locate a satisfactory final line for the 48 mile section from Swindon to Holyport about 815 miles of route were surveyed and studied: the routes to the north of Reading crossed the River Thames near Henley and Wallingford and were damaging to the environment of the "downs". Consequently the final route chosen between Tormarton and Holyport passed south of Reading and Swindon. The report produced for the South Eastern Road Construction Unit by the Consulting Engineers, which is included in the archive, describes the detail of these issues.

On the M5 the northern limit was fixed by the completed length of M5 north of Strensham in Worcestershire; for the length to the south of Bristol into Somerset a major issue was whether to pass east or west of Bristol. Whichever way the route went, the hills to the south of Bristol and Bath, posed major topographical problems but a western route served traffic from Avonmouth, the proposed Portbury Docks and movements from South Wales to the West Country more satisfactorily.

A route to the east of Cheltenham would have added distance and climbed into the higher Cotswolds whereas a line between Cheltenham and Gloucester served both places and avoided most of the steeper country. Hence the scheme line adopted passed to the east of Tewkesbury running approximately parallel, but not close to the A38 trunk road (originally a Roman road) then between Cheltenham and Gloucester towards the interchange site with the M4 at Almondsbury. The crossing of the tideway near Avonmouth plus the adjacent ground conditions dictated the need for a high level viaduct and the climb up the scarp slope to pass over the saddle in the Clevedon Hills beyond, all entailed considerable and exacting Civil Engineering Works. From the high ground near Clevedon the route crossed the first part of the Somerset Levels, then south of Weston-super-Mare through a saddle in the Mendip Hills into the second part at the approaches to Edithmead. From Edithmead the route passed East of Highbridge and Bridgwater. To the Southwest of Bridgwater a number of more remote options were examined, although the main corridor was south east of Taunton and Wellington joining up with the Cullumpton Bypass. The map which has survived shows these routes including some passing through the Blackdown Hills. The contribution from Brigadier (Stanley) Baldwin, is a good insight into how procedures worked and the efforts which were applied to achieve a satisfactory route.

The location of the Second Severn Crossing and the approach roads is well documented in the series of papers published in the Proceedings of the Institution of Civil Engineers Volume120 special issue2 entitled Second Severn Crossing.

Land Acquisition

Highway authorities in the past often attempted to acquire land for schemes by agreement, and if terms could not be agreed they sought powers to compulsory purchase. With the advent of the motorway programme this process would have placed heavy burdens on the Government’s District Valuation service and it was the Ministry’s policy to seek powers for compulsory acquisition sometimes at the same time as the scheme orders were processed. Statutory powers to acquire land were included in the Highways Acts 1959 and 1971, the Transport Act 1968 and the Land Compensation Act 1973. The procedure for acquiring land compulsorily is described in the First Schedule to the Acquisition of Land (Authorisation Procedure) Act 1946.

On the M5 there were eighteen major Compulsory Orders made and Public Inquiries were held into thirteen of them. Thirteen Supplementary CPO’s were also made and these required three Supplementary Inquiries.

Detailed Design

This summary cannot provide comprehensive information of all factors arising in the design of several hundred miles of motorway. The brochures produced for the opening of various sections of motorway and other documents give a picture of much of the detail and are included in this Archive. The following paragraphs give a commentary on the more notable issues as well as referring to anecdotal material which has been provided by a few people concerned with the projects.

During the years of the construction of the motorway programme there have been changes in the dimensions of the parts of the overall motorway cross section as shown in table 10.2 of the publication by Thomas Telford Ltd. "A history of British Motorways by George Charlesworth".

In the Southwest the motorways are all three lane roads except at the approach to the first Severn Bridge and where they pass through interchanges such as Almondsbury where the width is reduced to two lanes.

First Severn Bridge Crossing

As stated in the history earlier, Mott Hay and Anderson with Freeman Fox were the Consulting Engineers for the Severn Bridge, the associated Wye crossing and the approach roads. The contractors for the Severn Bridge substructure were Associated Bridge builders and John Howard was the contractor for the superstructure and the Aust Viaduct. The contractors for the Wye Bridge and Viaduct were Cleveland Bridge and the western approach road was constructed by Martin Cowley with Fitzpatrick. The eastern approach road was constructed by Costains. The surviving newspaper cuttings included in the archive give a valuable picture of the enthusiasm which existed at the time of the opening of the Bridge by Her Majesty The Queen in 1966.