Region: North West
M55 Preston Northern By-pass
The Road Plan for Lancashire 1949 included a number of 'second Group Routes', with one of their junctions defined as connecting large towns to a 'first Group Route'. A 'link' to Blackpool from the proposed North-South Motorway was such a route, with the intention that it should be designed and constructed as a 'motorway'.
When the Preston By-pass section of M6 was constructed in the late 1950's, its northern end connecting it with the A6 south of Broughton was planned to be the first part of the 'link', and filling was placed between the slip roads of the junction for this purpose.
In 1963, traffic problems were becoming so severe in the area that Lancashire County Council, Preston and Blackpool County Borough Councils and other local authorities in the Fylde instructed their Surveyors to produce a joint Report putting forward a reasoned case for the early construction of the Blackpool Link, as the route was then called. Supporting statements from the Chief Constables of Lancashire and Preston were included and the report stressed the following points :-
Following the submission of the Report to the Ministry, in March 1964, the County Council was authorised to proceed with surveys and preliminary design work, as the Minister's Agent.
In the same year, a re-appraisal of the traffic plans within Blackpool was carried out, which led to a change in the terminal point for the route from East Park Drive to Peel Hill. The route was therefore, amended, westwards from the proposed junction with Fleetwood Road, A585, north of Kirkham. Subsequently, the railway line from Kirkham to Blackpool South was closed, and a further variation was made in the alignment of the route, in order to utilise a length of the disused track.
On the formation of the North Western Road Construction Unit in April 1967, the responsibility for carrying out the preparatory work for the scheme passed to the Lancashire Sub-Unit.
In early 1969, a Feasibility Study was carried out into proposals for an East-West By-pass of Preston. It considered three proposals,
Preston Northern By-pass, extending to the Fylde Coast
Preston Southern By-pass, and
Preston Western By-pass
The Study Report published in September of that year concluded that, whereas the full network of By-passes would be required by 1980, Preston Northern By-pass merited the highest priority.
The Report had highlighted the high incidence of very serious and fatal accidents on the roads leading to the Fylde Coast. Since January 1959 a total of 376 fatal accidents had occurred within the Study area. With a high number of the accidents occurring within Preston itself, it accounted, to some extent, for the change in the naming of the Route from the 'Blackpool Link'.
After the consideration of possible alternative lines, the motorway, now designated M55, was included in the Minister's Firm Programme in October 1971, and the statutory procedures were begun. The Scheme did not involve the demolition of a single habitable dwelling and the number of objections was comparatively small. However, Public Inquiries were held during 1972 and the Statutory Procedures were completed without undue difficulty.
The project included the construction of approximately 11 miles of dual three-lane carriageway motorway, and half a mile of dual two-lane carriageways through the Broughton Interchange.
The completion of the Interchange with the A6 at Broughton involved the construction of two slip roads to the west of the existing roundabout. To the east of A6, the existing slip roads required amendment to provide a four-lane weaving section for eastbound traffic and a separated collector-distributor road for weaving westbound traffic. The existing trunk road A6 forms part of the national high load route network, on which headroom at bridges must be higher than normal. The number of high loads using the A6 through Broughton each year is very limited. Consideration was given to the most economical way of providing the headroom required and it was decided to construct a depressed route through the centre of the roundabout for use by high-load vehicles only. The alternative was to lift the level of the motorway, which would have involved a considerable additional expense in raising the viaduct and approach embankments, constructing additional retaining walls, lengthening the new slip roads and steepening the grades of the existing slip roads.
The Scheme also included the construction of a standard two-level interchange with the Kirkham-Fleetwood Road A585 at Corner Row, and slip roads connecting to Preston New Road A583 at Peel, where bridges carrying the roundabout were to be provided in readiness for the extension of the road westwards, at a later date.
In total, twenty-one overbridges, nine underbridges, the widening of an existing underbridge, a reinforced concrete box culvert, a farm underpass, two pedestrian subways, and two retaining walls, were required.
The design of the overbridges varied, depending upon the services and the class and width of road which they carry. Three have decks of continuous steel universal beams composite with reinforced concrete deck slabs and five bridges have decks comprising precast prestressed concrete inverted tee-beams with diaphragms and composite deck slab. Eight of the bridges, including three occupational bridges, are of three-span type with reinforced concrete cantilever side spans and precast prestressed concrete box beams in the centre suspended span. Two of the bridges are of four-span type comprising simply supported precast prestressed concrete box beams.
The most significant underbridge is the viaduct crossing of the existing Broughton Circle roundabout junction with Garstang Road A6. Almost 400 feet long, it comprises three suspended spans of precast prestressed concrete box beams, reinforced concrete frames for the intermediate supports and reinforced concrete slabs cantilevered from the abutments.
The bridging of the Preston-Lancaster Canal posed a stability problem with regard to the deep-seated peat layers under and adjacent to the crossing, particularly on the west side. To keep the peat excavation and embankment away from the canal, it was decided to incorporate an additional span in the bridge, which consequently has two equal spans of precast prestressed concrete shear-connected box beam construction, the land span of which on the west side also serves as an occupation bridge.
Considerable standardisation was achieved, by the use of precast concrete deck beams and the extensive use of elliptically shaped and rounded columns of equal size, which allowed standard shutters to be used. The standardisation of fascia detail permitted precasting, with a consequential high standard of finish.
The first Contract to be awarded was for the construction of the bridge carrying the motorway over the West Coast Main Line, in order that it could be completed in advance of electrification. Work began in September 1972 and the early completion of the bridge in July 1973 had the added advantage of providing access along the line of the motorway for use by the Main Contractor.
Tenders were invited for two separate Main Contracts, east and west of the Preston-Lancaster Canal. In the event, the same Contractor was successful in being awarded both and work began in May 1973
The deposits of peat which occur in many low lying or poorly drained areas, are remnants of the larger concentrations covering much of the Fylde in historic times. They have largely vanished as a result of the combined effects of natural erosion and agricultural drainage. In six areas along the route of the motorway, the peat had to be removed completely and backfilled to 12 inches below original ground level with imported free-draining material.
The largest of the areas at Mythop Moss extended over a length of 4000 feet where the peat, which reached a depth of over 30 feet in places, was underlain by soft alluvial silt and clay. The total volume of peat excavated in this area was almost 400,000 cubic yards and the sand used as backfill was obtained from a borrow pit which was opened-up between the existing and disused railway lines.
Material for backfilling was obtained from a nearby disused airfield at Inskip, where the runways were broken up and the land returned to agriculture.
In addition to the removal of peat some 21/4 million cubic yards of other excavation was necessary. 1¾ million cubic yards of selected filling was required the majority of which had to be imported from quarries up to 20 miles away.
In May 1974 work began on a further Contract for the diversion and widening of the existing Broughton to M6 southbound slip road over a length of almost one mile. Structural work included the extension of an existing reinforced concrete box culvert and the partial reconstruction of two overbridges.
Shortly before the M55 was due for completion, arrangements were made in conjunction with the Ministry of Defence, and the British Aircraft Corporation, for a Jaguar G R Mark 1 aircraft, from the Warton (Lancashire) Aerodrome, to land on the afternoon of Saturday, 26 April, 1975, on the road base of a section of carriageway near Weeton. After fitting four of the RAF's latest cluster bombs on the plane, it then took off from the motorway. The purpose was to demonstrate the Jaguar's ability to land and take off in short distances.
The motorway was opened to traffic in July 1975.
In 1971, the County Council and the Blackpool County Borough Council had jointly submitted to the Department of the Environment a proposal for a road known as the Squires Gate Link Road. It was to be an all-purpose road from the terminal roundabout of the M55, utilising a further one mile of the disused railway track bed, and would serve Blackpool South Shore and the Airport. It would also connect with the A574, a main route between Blackpool and Lytham St.Annes, by means of Squires Gate Lane.
In the same year, it was proposed that a further road should be constructed along the full length of the disused railway leading into the centre of Blackpool, and to be known as the Central Railway Route.
The two roads would each have a different function, but would be complementary to each other. Initially, priority was given, by the County Council, to the Squires Gate Link Road, but the Central Railway Route, subsequently to be named 'Yeadon Way', was constructed first and opened to traffic in January 1986. It provided a direct connection into major coach/car parking areas on the site of former railway sidings, and with a capacity equivalent to 6000 cars.
The construction of Squires Gate Link Road, and the dualling of Squires Gate Lane, were completed in May 1995.
A more detailed description of this scheme can be found on the Lancashire County Council Environment Directorate website.