1. Introduction

1.1 Scheme Background

The A14 is an all-purpose dual carriageway road, running from Felixstowe Docks tothe M1/M6 motorway junction, a distance of approximately 210 km. The A14 isdesignated the main east-west strategic route between the east coast ports and theMidlands and has European Route Network status. The section of the A14between Cambridge and Huntingdon also caters for north-south traffic between theM11 Junction 14 and the A1(M) at Alconbury.

The A14 through the Cambridge to Huntingdon corridor is heavily trafficked,carrying regional traffic and significant local traffic movements as well as strategicthrough-traffic, with a high proportion of heavy goods vehicles (HGVs).

1.2 Early Studies

Issues of congestion, journey time reliability and safety led to the Department ofTransport commissioning a number of feasibility studies into improving the A14 andits junctions between the M1-A1 link and the eastern end of the CambridgeNorthern Bypass (CNB). The following studies reported between 1990 and 1995:

In 1997, a series of Working Papers was produced by Mouchel, investigatingoptions for on-line improvement to dual 3-lane standard. Further studies weresubsequently suspended in the Government's review of the trunk roadsprogramme. However, the strategic importance of the A14 resulted in options forits improvement being considered as part of the Cambridge to Huntingdon Multi-Modal Study (CHUMMS).

1.3 Cambridge to Huntingdon Multi-Modal Study

CHUMMS was undertaken on behalf of the Department of Transport, LocalGovernment and Regions (DTLR) by a consortium led by consultants Mouchel. Thefinal report, which was published in 2001, recommended a strategy of highwayimprovements combined with a rapid transit (guided bus) system, village trafficcalming and other minor highway improvements.

The highway improvements recommended by CHUMMS are summarised asfollows:

The highway improvements element of the CHUMMS strategy was developedfurther in 2002/3, by Mouchel and Faber Maunsell, to assist the Highways Agencyin recommending the A14 Improvement scheme for entry into the TargetedProgramme of Improvements (TPI).

1.4 Consultant's Brief

The Highways Agency commissioned Atkins Consultants Ltd in June 2003 to act astheir consultant for progressing the A14 Improvement Ellington to Fen Dittonscheme through Stage 2 Scheme Assessment and Public Consultation, leading toa decision by the Secretary of State for Transport on the Preferred Route for thescheme.

The following extract from the Task Order signed with Atkins sets out the Secretaryof State's objectives for this project, which are:

Atkins was required to identify alternatives for improving the A14 between Ellingtonand Fen Ditton, undertake scheme assessment to evaluate alternatives in terms ofengineering, traffic, safety, economics and environmental impact, recommendschemes for Public Consultation and hence arrive at a preferred route.

The following factors were to be taken into account when identifying and evaluatingalternative routes:

1.5 Technical Reports

A review of the route options considered in previous studies was undertaken and anumber of alternative route options consistent with the recommended CHUMMSstrategy were identified. This initial study was reported in the Initial Route OptionsReport (IROR) in October 2003, where a number of alternative schemes wererecommended for detailed technical, economic and environmental appraisal.

Further route development work and value engineering was undertaken to optimisethe designs to meet the objectives of the brief whilst taking full account ofengineering, environmental and traffic considerations. Detailed technical appraisalof those final route options was reported in the Technical Appraisal Report (TAR) ofAugust 2004, which includes a recommendation of a Preferred Route for thescheme.

Detailed traffic modelling, forecasting and economic assessment of options ispresented in the following reports:

A detailed environmental assessment of route options was undertaken, requiringthe preparation of:

1.6 Objectives of the Stage 2 Scheme Assessment Report

The objective of this Stage 2 Scheme Assessment Report is to, by providing asummary of the technical reports described above, identify the factors to be takeninto account in choosing alternative schemes and the environmental, engineering,economic and traffic advantages, disadvantages and constraints associated withthose schemes.

The overriding aim is to enable the public and statutory bodies to comment onalternative proposals taking into consideration their environmental, economic andtraffic implications.

1.7 Structure of the Report

The Stage 2 Scheme Assessment Report is structured into a further five chapters:

1. Introduction

2. Existing Conditions

2.1 Existing Highway Network

The A14(T) in the Cambridge to Huntingdon corridor serves several purposes:

The highway network within the study area is illustrated in Figure 2.1 below and shows the extent of the area of interest for the A14 improvement study with the proposed A14 improvements extending between Ellington in the West and Fen Ditton in the east.

figure

Figure 2.1 - A14 Improvement Study Area

The existing A14(T) between Ellington and Fen Ditton is a dual two-lanecarriageway all purpose (D2AP) road with the exception of a small section betweenBar Hill Junction and Girton Interchange which is dual three-lane carriageway(D3AP). All crossings of the existing road are grade separated, passing either overor under the A14 preventing traffic from crossing two carriageways of traffic. Thereare however many locations along the road where direct access can be gainedfrom adjacent properties or land. The majority of these accesses do not have anyform of acceleration or deceleration lane running away from or to the accessrespectively, making entry and exit manoeuvres very dangerous. Lay-bys along theexisting route are substandard in terms of their geometry and location.

Along the existing route there are strategic interchanges within the trunk roadnetwork located at Brampton Hut (with the A1), Hinchingbrooke (with the A14(T))and Girton (M11 Junction 14). Of these, only M11 Junction 14 falls within theproposed improvements scheme.

Junction 14 is the intersection of the M11, A14 and A428 to the northwest ofCambridge. It is a limited movement interchange with no connections to or fromthe A428 west of the junction. Links provide turning movements between the M11and the A14 (east) and connect the A14 (west) to the A1307 Huntingdon Road intoCambridge.

East of Junction 14, there are full-movement, grade-separated junctions with thelocal highway network at Histon and Milton, and west-facing slip roads only areprovided at Fen Ditton.

The condition of the existing A14 pavement has been analysed using the HighwaysAgency Pavement Management System (HAPMS). The data from this systemrevealed that a large proportion of the pavement along the route is in poor oraverage condition and will require replacing in the short-term.

2.2 Traffic

Traffic on the A14 is characterised by high volumes of traffic, much of which isthrough traffic. Base year (2003) traffic flows are shown on Figure 6.7 in AppendixF. Traffic flows along the majority of the section of the A14 within the study areaare high. The recommended maximum flow per day for a dual two-lanecarriageway is 39,000 vehicles in each direction of travel. The observed flow in2003 between Galley Hill and Trinity Foot is 36,000 vehicles per day (92% ofcapacity), with 37,800 vehicles per day (97% of capacity) between Trinity Foot andBar Hill.

Travel speeds vary along different sections of the A14 trunk road during themorning peak. The Cambridge Northern Bypass generally operates well withaverage speeds in the AM peak of between 91 kph and 103 kph eastbound; and 84kph to 100 kph westbound. To the west, average speeds of around 65 kph havebeen observed in the AM peak between Godmanchester and Brampton Hut,whereas the section between Alconbury and Godmanchester generally performswell, although speeds in the AM peak drop to around 70 kph on the southboundapproach to the Godmanchester Junction. However, the section of the A14between Godmanchester and Bar Hill have the lowest observed speeds in themorning peak direction (eastbound) of around 45 kph. Average speeds pick upagain between Bar Hill and Girton to around 100 kph.

A further feature of existing traffic conditions on the A14 is the high percentage ofHeavy Goods Vehicles (HGVs) that use the route, which when combined with hightraffic flows contributes towards very poor travel conditions. At Swavesey, 25% ofvehicles using the road are HGV's, the majority of which are the largest type ofarticulated vehicle with four axles or more. On the Cambridge Northern Bypass theproportion of HGV's falls to 15%. These are very high figures given that thenational average for rural major trunk roads in Britain is 10%.

2.3 Accidents

Accidents are perceived as a significant issue on the A14. Analysis has shown thatthe number of accidents is not significantly different to other similar A roads, butthere is a high incidence of "slight" accidents - often minor shunts, reflecting thecongested traffic situation. This does not detract from some isolated seriousaccidents on the A14 in recent years. It is often the case that incidents on the A14(accident or breakdown) can quickly cause severe traffic jams over a wide area,with few diversion routes (other than on unsuitable local roads), presentingdifficulties for emergency services to quickly reach incident locations.

A summary of the analysis of accident data along this section of the A14 over thepast 5 years is given below:

2.4 Geological and Geotechnical Conditions

2.4.1 Geology

Information on the geology of the study area was obtained from the historicalgeotechnical investigations, 1:50,000 British Geological Survey Maps, (Sheet 187for Huntingdon and Sheet 188 for Cambridge), 1:10,000 digital British GeologicalSurvey Map for Cambridge, and the memoirs that accompany them. The geologyof the study area is shown on drawing number 5021044/DR/GI/001.

A significant proportion of the study area between Ellington and the East CoastMainline Railway (ECML) overlies gravel bearing deposits, generally terracegravels of the River Great Ouse and Ellington Brook. Between Hemingford Abbotsand Conington, the study area is underlain by gravel bearing deposits, generallyTerrace Gravels of the River Great Ouse. The elevated sections of the study areaare expected to have an upper mantle of Glacial Till. The solid geology, whichoutcrops on the flanks of the hills, is Oxford Clay.

The solid geology outcropping in sequence eastwards from Fenstanton to Bar Hillconsists of Oxford Clay, Ampthill Clay, Kimmeridge Clay and Lower Greensand.A significant proportion of the study area between the M11 Junction 14 and FenDitton is covered by gravel bearing deposits, generally Terrace Gravels of the RiverCam. The solid geology east of Bar Hill consists predominately of Gault Clay, withsome Lower Chalk at the extreme eastern end.

2.4.2 Hydrogeology

The general underlying solid geology between Ellington and the A1198 atGodmanchester consists of clay strata where only negligible flow of groundwater isexpected, and is classed as non aquifer.

Aquifers with high yields have been recorded within the Terrace Gravels.Extensive excavations have been undertaken within these deposits and have nowformed several large ponds of open water. The water levels are generally 1 to 2mbelow the general ground level.

A significant number of ponds have been identified, generally located within theTerrace Gravels near the River Great Ouse or other tributaries.

Between the A1198 and Fenstanton the underlying geology consists of TerraceGravels, Glacial Till and Oxford Clay. The Elsworth Rock formation is consideredas a minor aquifer with soils of intermediate permeability.

Additionally the Lolworth Spring occurs to the west of Bar Hill where the AmpthillClay outcrops below the Kimmeridge Clay.

The main recorded aquifers east of Bar Hill are the Lower Chalk and the LowerGreensand. The relatively impermeable Gault Clay separates the LowerGreensand and Lower Chalk horizons. This horizon of clay is confininggroundwater within the Lower Greensand aquifer and as a result the groundwaterwithin the aquifer may be under artesian conditions.

This aquifer is classified as the second most important aquifer in the regionbetween Maidenhead and Cambridge. The Lower Greensand outcrops near BarHill where springs have been recorded flowing from the base of the formation.Groundwater levels are within approximately 2m of the ground surface in the RiverTerrace Deposits, and vary between 1m and 6m below ground level in the LowerChalk outcrops.

2.4.3 Existing Earthworks

The existing A14 at Ellington is generally constructed on embankment and crossesseveral culverts, which flow north towards the Ellington Brook. Continuing east fromEllington the A14 mainly follows the existing ground level until reaching Huntingdonand later Godmanchester which it passes through on embankment.

As it begins to pass through Huntingdon the A14 crosses over the East CoastMainline (ECML) railway, which has encountered slope stability problems in thepast. The side slopes of the railway embankments and cuttings are approximately 1in 2. Stability of these slopes has been improved by locally battering back theslopes to a 1 in 3 gradient, the construction of gabion and pile reinforcement, andinstallation of slope drainage measures.

The existing A14 east of Godmanchester to the M11 Junction 14 is generally atgrade but has occasional sections formed on low embankments, with severalculvert crossings.

From the M11 Junction 14, the CNB passes through the Girton cutting. The slopesof which are approximately 7.5 metres high. East of the cutting the CNB has beenformed on embankment until it reaches the River Cam crossing. The stability ofthis embankment has been recorded as being marginal since the construction inthe late 1970's. Previous investigations indicated the marginal stability was due toover-steepening of the embankment slopes (up to 1:2) and not determiningappropriate design parameters for Gault Clay. These investigations generallyrecommended reinforced earth slopes as a remedial measure to improve thestability of the embankment. Up to 100 slope failures have been recorded on theCNB to date.

2.4.4 Contaminated Land

There are several filled gravel pits within the study as well as a number of landfillsites, both historical and currently operational. The landfill sites that affect theproposed route options include Buckden (North and South sites), Fenstanton,Conington and Milton. In addition to the landfill sites there is a potential forcontaminated land to be present, particularly in areas associated with commercialand industrial activities.

LANDFILL SITES

The following section briefly describes the four main landfills, which lie within closeproximity of the proposed road scheme.

BUCKDEN LANDFILL

The landfill site at Buckden lies between the villages of Brampton and Buckden.The landfill site itself is split into two sites: the original "south" site, which is nowclosed and restored, and the currently operational "north" site. Buckden Southlandfill is known to have operated between the 1930's and 1994. The landfill wasnoted as having received a wide variety of wastes including domestic refuse,animal carcasses, contaminated materials, Special Wastes including asbestosproducts, and certain clinical wastes. Liquids are also thought to be present withinthe landfill including non-specific liquids, sludges and on-site leachate. Landfill gasand leachate collection and treatment systems are still in operation on site.

Buckden North landfill is currently operational and contains a variety of differentwastes including approximately 75% household and commercial wastes, 15% solidindustrial wastes, 8% inert/construction materials and 2% others, which includeleachate, liquids and low level clinical (hospital) wastes. Wastes were initiallyreceived at the Buckden North site in 1989, and landfilling continues on the site tothe present day.

An area of unlicensed historic landfill is also believed to be present to the west ofthe Buckden North landfill site. This tip is thought to contain demolition materialsand although the tip is unlikely to be engineered, the nature of its contents wouldsuggest that impact to the surrounding environment will be minimal.

CONINGTON

The closed landfill at Conington lies just to the south of the existing A14. Thislandfill is reported to contain 60,000 tonnes of blue asbestos contaminated soil,domestic waste and inert (concrete wastes) materials. The actual extent of theConington Landfill is unknown at this time and there is no specific data as to whenthe filling and capping of the site was completed. The landfill forms a mound,which is topographically higher than surrounding ground level, including theexisting A14. Passive gas venting is still present on the site, approximately 20-25msouth of the A14. The Environment Agency indicates that no active controlmeasures are in place for either leachate or landfill gas.

MILTON

Milton landfill lies to the north east of the Milton Junction between the CambridgeNorthern Bypass and A10(T). The landfill was initially created by the excavation ofthe Gault Formation, which was first noted on Ordnance Survey maps in 1992.The site is currently operational with new wastes being landfilled at the far northeasternportion of the landfill, which is a significant distance away from the existingCNB. Although the proposed route of the CNB does not impact upon Milton landfill,the existing slip road from the A14 to the A10 junction represents the southernboundary of the landfill and therefore older wastes are likely to be present adjacentto the slip road.

The licence for this landfill site indicates that it is capable of accepting civil amenitywastes such as inert wastes, household waste, difficult and certain clinical wastes.In addition the landfill also accepts small amounts of special wastes, asbestos andcertain radioactive substances. Recent estimates indicate that the landfill sitetypically receives up to 250,000 tonnes per year.

In addition to Milton Landfill, a series of pits were excavated to the west of thelandfill site and to the north of the existing Cambridge Northern Bypass, between1927 and 1952. It is unclear as to the original purpose of these pits as they areshown to lie on the Gault formation by the geological maps. The pits lay just to thenorth of the sewage works that was described as a sewage farm and they mayhave had some connection with the sewage farm operations.

A portion of the pits was noted to have been backfilled between 1952 and 1974,just to the north of the existing Cambridge Northern Bypass. However, noinformation is available as to the materials that have been used in the backfill.

2.4.5 Potential Contaminated Sites

In the vicinity of Brampton village, to the north of the existing Buckden North landfillsite a former petrol station is present. In addition a historic scrap yard is known tohave been present just to the south of the Buckden South landfill, while an existingfuel distribution depot is also noted to be present in this area.

In the area around Fenstanton and Fen Drayton a number of existing and formerpetrol stations are present. In addition vehicle repair garages, a coach depot, ahaulage distribution centre, a sewage treatment works and several manufacturingindustries all lie within close proximity to either the existing A14 or the proposedroute alignments.

From Bar Hill to Fen Ditton the main potential areas of likely contamination relate tohistoric contamination associated with a former railway yard and a sewagetreatment works, which is still operational at present. Both of these features areknown to have historically extended beneath the existing A14 and therefore maypotentially impact future road construction. The remaining areas of contaminationconcern are related to industrial processes that are present on industrial estates inthe vicinity of the Bar Hill and Milton junctions.

2.5 Existing Structures

There are eighty-one existing structures within the improvement scheme area.They may be classified into six groups, as shown in Table 2.1.

Table 2.1 - Existing Structures
Type of Structure Number
Overbridges 27
Underbridges 20
Underpasses or Subways 4
Culverts 19
Sign Gantries 6
Retaining Walls 5

The location of each structure is shown on drawing number 5021044/DR/BR/001.

The bridges within the improvement scheme area were generally designed andconstructed in the 1970s and 1980s. Repairs, strengthening and modifications willbe required to some existing structures and will be incorporated into the schemewhere appropriate. Several structures have not been assessed to currentassessment standards and will need to be so assessed before the extent of anystrengthening can be finalised.

It has been assumed that the improvement scheme will be used as an opportunityto replace elements that are likely to reach the end of their design lives within tenyears of projected opening. Such elements include bridge deck waterproofing onunderbridges, bearings and parapets.

2.6 Public Utilities

Available drawings of Statutory Undertakers' (SU) apparatus indicate that thefollowing SU companies have plant located within the study area:

2.7 Environmental Aspects

The proposals for improvement of the A14 between Ellington and Fen Ditton willpotentially affect a large study area, impacting on environmental topics such as:

The geology of the area has been described previously.

The main environmental features and designations within the study area are shownon the Environmental Constraints drawings, numbers 5021044/DR/EN/ 01 to 03.

The following summarises the existing environmental conditions, fuller descriptionsare included in Chapter 5 of this report.

2.7.1 Traffic Noise and Vibration

The study area for the traffic noise assessment has been split into level of detail:

Noise levels in the study area have been predicted using noise modelling software.To provide information on the existing noise levels in rural areas where it was notreasonably possible to carry out noise calculations, a preliminary noise survey wasundertaken. The measurements concentrated on areas where existing levels arelow or where local roads may have some effects.

The findings of the noise survey have been taken into account when assessing theexisting conditions. Areas adjacent to the existing A14 that are exposed tosignificant levels of noise from the present A14 are described asbelow, all noiselevels are in terms of LA10 (18 hour).

From the western end the area is open countryside with isolated dwellings situatedat some distance from the A14 and A1, levels were measured above 50dB exceptat Brampton Wood. Calculations confirm that most of the area of this woodland isbelow 50dB. Calculations of noise levels indicate that levels of 60dB or maoreaffect all areas within approximately 250m to 300m of the A14 and A1M but nearthe junction the combination of the two sources extends noise over a wider area.Levels of 55dB or more may extend as far as 600m and in some places, greaterdistance near the junction.

Housing areas on the western side of Brampton have noise levels in the low 60sdB at the nearest houses and 55dB or more up to 500m. Between the A1 nearBrampton and the A141 near Stukeley Junctions the existing A14 affects houses onthe north side of Brampton with most above 55dB at up to 500m distance. AtHitchingbrooke Coutry Park, which is partly on ground rising from the road, noiselevels of 55dB or more are found within 700m each side of the A14 with additionalnoise from the B1514 thus affecting most of the park and the racecourse.

Continuing westwards, on the northern side of the A14 there are extensive housingareas of Stukeley and the southern side of Huntingdon. Noise levels are 60dB ormore within 200m of the A14 and 55dB or more within approximately 400m. Partsof Hinchingbrooke Hospital, which is on ground rising from the road, are exposed tolevels above 55dB. Within areas to the east of the B1514, those to the north of theB1044 and west of the A1198, there are further areas of housing close to the A14.Noise levels are 60dB or more within 150 to 200m of the A14 and 55dB or morewithin 300 to 600m and further where there are additional contributions of noisefrom other roads.

To the west the A14 traverses a more open area to the south of Hemingford Abbotsand Hemingford Grey. There are isolated houses on both sides with housingdevelopments on the southern side of Hemingford Abbots and Hemingford Greysomewhat further back. Noise levels are 60dB or more within 250m of the A14 and55dB or more within approximately 500m. The more distant effects of traffic noisewith levels of 50dB or more affects the southern side of Hemingford.

The noise environment to the east of Galley Hill is similar in that it traverses openareas to the south and east. There are a few isolated houses on both sides withsubstantial developments at Fenstanton. Noise levels are 60dB or more within 250to 300m of the A14 and 55dB or more within 500 to 600m but less within thehousing at Fenstanton on account of the existing environmental barriers. FenDrayton is affected by distant A14 noise with levels of approximately 50dB on thesouthern fringes.

Between the Bar Hill and the M11 Interchange at Girton noise levels are 60dB ormore within 300m of the A14 and 55dB or more within 500 to 600m but less withinthe housing area of Bar Hill.

Lolworth is affected by levels in the low 50s dB and some of the northern fringes ofBoxworth may be above 50dB due to the local road even where they areunaffected by local traffic. However, at Conington houses away from the local trafficexperience noise levels of less than 50dB.

At the eastern end of the scheme the area adjacent to the existing CambridgeNorthern Bypass is characterised by the open area near the M11 and villages andhouses adjacent to the bypass. Noise levels are60dB or more within 300m of theA14 and 55dB or more within 600m. However at Girton, where the road is incutting, houses up to 180m are affected by levels of 60dB or more with thoseclosest in the 65 to 70dB range. Similar levels affect the nearest houses aroundHiston Junction.

2.7.2 Air Quality and Greenhouse Gases

At the roadside of the A14, current measurements show that there have beenexceedances of both the annual and 1-hour mean nitrogen dioxide objectives, andthe 24-hour mean PM10 objective. However, as the closest properties to the A14are located at a greater distance from the road than the monitors, thenconcentrations at properties, where people are exposed, are likely to be lower.

Currently, air quality objectives are expected to be achieved at properties in thearea, and no air quality management areas within the A14 corridor have beendeclared to date. Further investigation is taking place near Bar Hill, Girton, Histonand Impington by South Cambridgeshire District Council.

Initial results from the nitrogen dioxide diffusion tube monitoring survey carried outby Atkins, suggest that concentrations are expected to meet the annual mean AQSobjective at all locations, except those within 10m from the roadside.

2.7.3 Land Use and Agriculture

The majority of the study area, particularly the western half, comprises of Grade 2and 3a agricultural land. The study area extends from the east of Cambridge to thewest of Huntingdon. A number of smaller settlements line the route corridor.

There are a number of significant developments located within the route corridorincluding landfill site (described previously), Beaconsfield equestrian centre, golfcourses at Brampton and Hemingford Abbott, Cambridge Services at Swavesey, ashopping centre at Bar Hill, Cambridge Crematorium and Cambridge Science Parksouth of the A14 at Milton. There are a wide range of privately owned agriculturalenterprises located throughout the study area.

There are a number of on-going planning applications and development proposalswithin the study area. These are listed in the Environmental Assessment Report. Ofthese the two major developments are:

2.7.4 Landscape and Townscape

The character of the existing A14 varies significantly along its length includingsections through built areas such as Huntingdon then sections through anagricultural landscape before following around the northern edge of Cambridge.

At the western end the A14 approaches Godmanchester on flyover from the eastwith extensive views from the road, the high bay warehouses at Cardinal Parkdistribution park to south and landfill site and allotments to north are clearly visible.Roadside vegetation / environmental barriers then enclose the views, allowingglimpses (attractive) from the road to flood meadows, parts of the historic towns,church spires, old buildings. Impressive water tower adjacent to A14 on south sideforms landmark view. Views particularly open out where the A14 is on flyover orviaduct over the river Ouse and east coast main railway.

As the A14 leaves Huntingdon on the western fringes views north are eitherenclosed by vegetation or to housing/ commercial areas and to the south opengreen space.

This area includes the low lying character area of the river Ouse to the north andthe undulating topography of the Western Claylands to the south. The existing A14passes through the southern fringes of Fenstanton which reduces the roads impacton the wider rural landscape. At the eastern edge of the town, housing estates arevisible to the north with the south being more open with remnant orchards stillevident close to the road, views are then restricted by close boarded environmentalbarriers and dense vegetation. There is significant visual clutter with road signs,service station and bus garage, Dairy Crest factory and poultry sheds. Severaloverbridges along this section.

To the west of Fenstanton views open out and Hemingford Abbot and HemingfordGrey can be seen to the north, whilst mature Willows on the south side enclose theviews and denote the large water bodies of the disused gravel workings at GalleyHill.

2.7.5 Occasional Road Side Properties

ECOLOGY AND NATURE CONSERVATION

The A14 study area chiefly falls within English Nature's 'West Anglian Plain NaturalArea'. Some key characteristics of the area are:

The Environmental Constraints drawings, summarise information on statutory andnon-statutory designated sites and records of legally protected species.

The most important woodland in the area is Brampton Wood SSSI. At 132 ha,Brampton Wood is one of the largest remaining blocks of ancient woodland inCambridgeshire. There are a number other SSSI's in the study area includingBrampton Meadow SSSI and Portholme Meadow cSAC (Candidate Special Area ofConservation)/ SSSI, a flood meadow relict from the old drainage system. To thewest of Hemingford Grey Village, on the south side of the existing A14 is theHemingford Grey Meadow SSSI, a species-rich meadow of the calcareous claypasture type, a type restricted nationally to the south of the country and decliningdue to the changes in traditional management practices.

In addition the study area has extensive areas designated as County Wildlife Sites,including a neutral grassland site, Buckden Pits SSSI, a series of flooded gravelpits adjacent to the Ouse and the River Great Ouse, the citation for whichcomments "in Huntingdonshire the flood plain is often wide and contains extensiveareas of semi-natural riparian habitat. The flood plain has been heavily exploited foraggregate extraction and the majority of the gravel pit complexes are now CountyWildlife Sites in their own right." At the eastern end of the study area the A14,Cambridge Northern Bypass crosses the River Cam, also designated as a CountyWildlife Site.

Surveys have been undertaken for species afforded protection through legislation,these include badgers, bats, common otter, hazel dormouse, amphibians andreptiles, water vole, wild birds and white-clawed crayfish. An extended Phase 1Habitat Survey has also been undertaken. The study areas for these surveysextend approximately 500m either side of the route options, including the on-linesections of the A14, the exception being for breeding birds where survey effort wasfocused within a 500m corridor of the off-line section.

CULTURAL HERITAGE

The A14 is broadly based on the line of a Roman Road connecting Cambridge withGodmanchester and known as the Via Devana. Important military bases werelocated at Cambridge and Godmanchester and later civilivan settlements weredeveloped. The nature of buried archaeological remains located in proximity to theA14 is likely to be in the form of small scale Iron Age and Romano-Britishsettlements or individual rural farmsteads. Remains have been recovered along theroute of the A14 dating from the Palaeolithic period through to the Post Medievalperiod. A number of villages now lie in proximity to the A14 and many of theseretain their medieval and post medieval nature, recognised in the many ListedBuildings or Conservation Area designations within the villages such as at Ellingtonand Fenstanton. Equally some milestones are Listed along the course of the A14dating to the 18th and 19th centuries.

PEDESTRIANS, CYCLISTS, EQUESTRIANS AND COMMUNITY EFFECTS

Access to the countryside via Public Rights of Way (PROW) provide importantrecreational interests for local residents. PROW are made up of footpaths,bridleways and byways. These are illustrated on the Environmental Constraintsdrawings.


2. Existing Conditions

3. Scheme Proposals

3.1 Description of Scheme Options

As discussed below a wide range of scheme options have been identified anddeveloped prior to the technical appraisal stage of this commission. From these,three principal route options (plus local alternatives) and four junction strategieswere taken forward for full technical, environmental and economic appraisal.

As mentioned in Section 1.6 this Scheme Assessment Report aims to summarisethe technical appraisal process. However, in doing so it will only concentrate onthose route options that the technical appraisal has shown as being most likely tomeet the objectives and limitations of the scheme brief. These options aredescribed below.

3.1.1 Do-Minimum Option

A Do-Minimum scenario has been developed to represent the most realistic view oftransport conditions without improvements to the A14. This allows comparisons tobe drawn in terms of traffic and environmental issues between the Do-Somethingscenarios, described below, and a baseline scenario.

In the Do-Minimum scenario only committed transport schemes and land-useproposals within the study area have been considered as shown in Figure 3.1.These are listed in Table 3.1.

Table 3.1 - Committed Highway Schemes Within Study Area
Scheme Improvement
A428 Hardwick to Caxton Common Dualling of existing A428
A1198 Papworth Bypass S2AP bypass of Papworth village
Milton Junction Safety Improvements
Access to Cambridge Science Park Double right turning lanes
Milton Junction Provision of dedicated left turn

Together with the schemes above it has been assumed that a replacementHuntingdon Viaduct and upgrading of the local road network around the proposedNorthstowe development will be required should the A14 Improvement scheme notbe implemented. These are described in more detail in the following sections.

figure

Figure 3.1 - Do-Minimum Option

HUNTINGDON VIADUCT

Huntingdon Railway Viaduct is a six span structure carrying the A14(T) over theB1514 Brampton Road and the East Coast Main Line Railway on the western sideof Huntingdon. It was constructed circa 1975.

The Do-Minimum assumption for assessing the A14 improvement options is basedon the premise that the existing Huntingdon Viaduct will be replaced. It is proposedthat the viaduct will be replaced with a structure similar to that shown in drawingnumber 5021044/DR/BR/023.

NORTHSTOWE

The proposed Northstowe development is not a committed scheme itself. However,based on information set out in the County Structure Plan it has been assumed ascommitted for the purpose of the Do-Minimum scheme.

To accommodate the increased traffic flows that will result from Northstowe the Do-Minimum Option assumes that the B1050 Hatton's Road carriageway will beupgraded to Dual 2 Lane All Purpose (D2AP) road between Northstowe and theexisting A14 and that this will feed into a new Bar Hill Junction. Improvements tothe local road network will also be made by running a local access road adjacent tothe northern perimeter of the A14 between Bar Hill and Dry Drayton, as shown inFigure 3.2.

3.1.2 Blue Route Option

A14 MAINLINE

The Blue Route Option is similar to the Targeted Programme for Improvement(TPI) route as detailed in CHUMMS. It is shown on Figure 3.3 and in more detail ondrawing number 5021044/DR/HW/101 and 102. As the drawings show, theproposed A14 mainline leaves the existing A14 corridor to the west of the A1/A14Brampton Hut Junction and runs adjacent to both sides of the A1 creating a singletraffic corridor. The eastbound carriageway crosses the A1 (options have beendeveloped to cross either over or under) and runs to the east whilst the westboundcarriageway remains to the west. The two carriageways join one another to thesouth of Brampton and the route moves eastwards passing between the town ofBrampton and Buckden North Landfill Site. It then crosses the River Great Ouseand East Coast Mainline (ECML) railway and continues in an easterly direction tothe north of the Wood Green Animal Shelter and the villages of Hilton andConington. It passes to the south of Fenstanton and the closed Conington LandfillSite before tying into the existing A14 to the south of Fen Drayton.

figure

Figure 3.2 - Northstowe Do-Minimum Option

figure

Figure 3.3 - Blue Route Option Mainline

From this point the Blue Route Option comprises online widening of the existingA14 and the Cambridge Northern Bypass (CNB) to Fen Ditton with the exception ofa short section at Bar Hill. At this location the route moves offline to the north of BarHill between Lolworth Spring and the Girton Interchange by a distance of 110metres at its maximum point to allow a new junction to be constructed to replacethe existing one.

In locations, where the Blue Route Option involves widening the existing A14,provision will be made for local traffic in the form of a Local Access Road (LAR). Inmost cases, the LAR runs adjacent to the proposed A14 mainline and ties into theexisting A14 when the route option moves offline. This maintains the route of theexisting A14, which will be used for local traffic when the proposed scheme isoperational.

The alignment of the Blue Route Option is discussed in more detail in Section 4.2of this report.

Junction Strategy

The Blue Route Option has nine associated junctions, as listed below:

Two junction strategies have been developed which include variants of each ofthese junctions together with alternative mainline cross-sections and Local AccessRoad layouts. These strategies are described in Section 4.2.2.

3.1.3 Purple Route Option

A14 MAINLINE

The Purple Route Option is shown on Figure 3.4 and in more detail on drawingnumber 5021044/DR/HW/103. As can be seen it follows the same route as theBlue Route Option from where it leaves the existing A14 at Brampton Hut to east ofthe Wood Green Animal Shelter. From this point the proposed A14 turns andtravels in a north-easterly direction before tying into the existing A14 to the west ofGore Tree Farm. It commences in an easterly direction along the route of theexisting A14, passing through Fenstanton and south of Fen Drayton. After passingFen Drayton the Purple Route Option runs along the same line as described for theBlue Route Option in Section 3.1.2 above.

JUNCTION STRATEGY

The Purple Route Option has nine associated junctions similar to those listed forthe Blue Route Option. The difference being that the Purple Route Option has ajunction at Galley Hill and no Fen Drayton Interchange.

Only one junction strategy has been developed for the Purple Route Option, whichis described in Section 4.3.

3.1.4 Orange Route Option

A14 MAINLINE

The Orange Route Option is shown on Figure 3.5 and in more detail on drawingnumber 5021044/DR/HW/104 and 105. As with the Blue and Purple Route Optionsthe commencement of the Orange Route Option is to the west of the existingBrampton Hut Junction with the A1. From here the route travels adjacent to thewest of the A1 and in doing so maintains one corridor of traffic in this area.

After crossing the A1 between Brampton and Buckden the Orange Route Optionpasses to the south of Buckden Landfill Site before crossing the River Great Ouseand East Coast Mainline. It continues eastwards to the south of the Wood GreenAnimal Shelter and north of the villages of Hilton and Conington. To the west ofConington is where the Orange Route Option begins to follow the same route asthe Blue Route Option, which it continues to do through to Fen Ditton.

JUNCTION STRATEGY

As with the Blue Route Option, the Orange Route Option has nine associatedjunctions, as listed below:

figure

Figure 3.4 - Purple Route option Mainline

figure

Figure 3.5 - Orange Route Option Mainline

Two junction strategies have been developed which include variants of each ofthese junctions together with alternative mainline cross-sections and Local AccessRoad layouts. These strategies are described in Section 4.4.2.

3.2 Cost Estimates

3.2.1 Basis of Estimates

Estimated costs for each scheme option have been calculated using basicquantities measured from preliminary design information. Table 3.2 below providesa breakdown of the estimates and the sections that follow describe associatedspecial factors and additional costs.

Where it was not considered practical to develop the design to a standard enablingdetailed quantification, an assessment of quantities or suitable allowance has beenmade. Unit rates have been obtained from various reference projects and appliedto the quantities as appropriate.

Costs are estimated to third quarter 2001 (Q3/2001) to enable them to be readilycompared to the Highway Agency's current Scheme Budget and previousestimates prepared for the HA.

Table 3.2 - Route Option Cost Estimates
Scheme Element Do-Minimum £m Blue (Junction Strategy A) £m Blue (Junction Strategy B) £m Purple £m Orange (Junction Strategy A) £m Orange (Junction Strategy B) £m
Preliminaries 0.430 26.043 27.138 25.556 26.124 27.197
Roadworks 2.184 87.052 88.728 86.522 87.214 88.849
Earthworks 0.314 39.909 39.711 28.498 36.539 36.214
Structures 26.513 94.872 98.971 95.156 98.919 103.018
Land 0.042 6.548 6.590 6.889 5.971 6.013
SU 0.300 15.994 16.249 17.781 15.278 15.533
Preparation & Supervision 0.492 34.641 35.542 33.265 34.668 35.544
Contingencies/Allowances 2.264 227.70 231.123 220.889 227.645 230.967
TOTAL 32.539 523.759 544.052 514.556 532.358 543.335

3.2.2 Special Factors

PRELIMINARIES AND TRAFFIC MANAGEMENT

Based on recorded data from previous contracts an allowance of 8% of theestimated construction costs has been made for preliminaries, excluding trafficmanagement. Traffic management has been assessed on a route specific basis toreflect the complexity of on-line widening.

SITE CLEARANCE

Huntingdon Railway Viaduct carries the existing A14 over the B1514 BramptonRoad and the East Coast Mainline Railway on the western side of Huntingdon. Ifthe new A14 is constructed the existing A14 will be detrunked and the viaductremoved and replaced with an at-grade junction at Brampton Road. The costestimates for each route includes an estimate of the cost of demolishing the viaductand replacing it with an at grade junction. All the costs associated with thedemolition of the viaduct; including those for the junction earthworks and pavementhave been included under the heading of demolition within the site clearancesection of the estimate.

EARTHWORKS

As the area is predominantly agricultural an estimated depth of topsoil for removalhas been established as 300mm.

The amount of acceptable material likely to be obtained from cuttings has beenassessed from examination of the geological data to hand. It has been assumedthat all unacceptable material will be placed in environmental bunds to avoid thecosts associated with transport and deposition to landfill sites.

There is generally a shortfall of acceptable material. Potential sites for borrow pitshave been identified along the proposed routes and so it is assumed that a fairproportion of the shortfall will be acquired in this manner.

COMMUNICATIONS

The cost estimates include allowances for emergency telephones, traffic surveyequipment, Close Circuit Television (CCTV) and Traffic Control Centres (TCC)Scheme equipment. It is possible that funding for TCC systems may be moreappropriately obtained from other budgets, but with the work still being undertakenwithin the A14 Scheme.

3.2.3 Supplementary Costs

An estimate for soft landscaping has been made from experience of typicalprovisions for similar schemes.

Diversion estimates have been requested from the various utilities companieswhose apparatus will be affected. Where estimates were not forthcoming,provisional assessments have been included in the estimates.

Land Acquisition Costs are to be estimated by the District Valuer. Atkins haveprepared drawings of land take for the various options and this has enabled a moredetailed cost estimate to be produced than would have been possible when theScheme Budget was established. The land take is predominantly agricultural and arate of £7,000 per hectare has been obtained from the DEFRA (Department forEnvironment, Food and Rural Affairs) website. In addition, development land to thesouth of the Cambridge Northern Bypass has been identified. The developers haveplanning permission for homes on the site between Histon Interchange and theImpington Rail Bridge and compulsory purchase of a strip of land will be necessaryto allow widening at the location. The cost of acquiring this land has been reviewedand an approximate value included in the estimates.

The cost of compensation for noise (Part 1 Claims) is to be estimated by theDistrict Valuer. As we have no better information at this stage we have included theScheme Budget allowance for Part 1 Claims in the cost estimates.The allowance for Preparation and Supervision has been reviewed. Werecommend that a total of 13% of the value of the works be applied for this,comprising 8% for preparation and 5% for supervision.

3.2.4 Developer Contributions

Between Bar Hill and the M11 Junction 14, the scheme has been appraised tomake provision for proposed development at Northstowe. It is possible that acontribution will be received from the developers however the scale of such isunknown and therefore has not been taken into account in the cost estimates atthis stage.

3.2.5 Detrunking Existing A14

No allowance has been made in the estimate for detrunking the A14 except for theremoval of Huntingdon Railway Viaduct and the associated at-grade junction withBrampton Road.

3.2.6 Comparison of Estimates

The estimates in Table 3.2 show the Blue Route Option (with Junction Strategy B)as the most expensive and the Purple Route Option as the cheapest.Significant variances between the elemental estimates are commented on below.

EARTHWORKS

The earthworks required for the Blue Route Option is significantly higher than theothers due to the greater imbalance between cut and fill, resulting in a far greatervolume of imported material required.

Although the Blue and Purple Routes follow the same alignment at the westernend, the Purple joins the existing A14 alignment earlier and therefore utilises moreof the existing carriageway, thus reducing earthworks requirements.

STRUCTURES

The estimates for structures vary between the routes. The cost of overbridges,underbridges and viaducts for the Orange Route Option is approximately £4m morethan for the Blue Route Option. This is predominantly because of the longer viaducton the Orange Route Option spanning both the River Great Ouse and the EastCoast Main Line.

The Galley Hill junction, unique to the Purple Route Option, requires extensivereinforced soil walling between slip roads and the main line, resulting in asignificant difference in the estimate for retaining walls.

VAT

The A14 Improvement scheme is a combination of new road construction builtoutside the existing highway boundary, on which VAT is non-recoverable, andonline widening on land within the highway boundary, on which VAT is recoverable.Therefore, because the Purple Route Option has the greatest extent of on lineconstruction the total amount of VAT for this option is lower than the other routes.


3. Scheme Proposals

4. Engineering Assessment

4.1 Introduction

This chapter presents a detailed engineering assessment of the route options interms of highway alignment, junction layouts, existing and new structures,geotechnics and contaminated land, earthworks, public utilities and compliancewith Standards. Significant engineering difficulties associated with route optionsare also identified.

Reference should be made to Table 4.1 in Appendix A, which provides acomparison of the route options for each of the above engineering parameters.

4.2 Blue Route Option

4.2.1 Mainline Alignment

The alignment details of the Blue Route Option are shown on drawing numbers5021044/DR/HW/202, 203, 205 to 207, 209, 230 to 234 and 240 to 241. As shownon the drawings the proposed Dual 2 Lane All Purpose (D2AP) A14 mainlineleaves the existing A14 corridor to the west of Brampton Hut Junction and headssouth towards the A1 corridor. On approaching the A1 the eastbound carriagewaymoves away from the westbound carriageway and can either rise on embankmentto cross over the A1 or move into cutting to pass beneath the A1. After crossing theA1 the carriageway then returns to follow the existing ground level as the alignmentruns parallel to the A1 and passes beneath the realigned Brampton - GrafhamRoad.

Adjacent to Brampton - Grafham Road, the A1 southbound to A14 eastbound linkdiverges to join the A14 eastbound carriageway as a lane gain turning the A14 intoa Dual 3 Lane All Purpose (D3AP) road east of the A1. Due to traffic volumesbeing higher on the A1 southbound to A14 eastbound slip, the slip road becomesthe mainline and the A14 eastbound merges in from the left.

At the point where it separates from the eastbound carriageway, the westboundcarriageway runs adjacent to the northbound carriageway of the A1, which itcrosses as it turns to move in an easterly direction and rejoin the eastboundcarriageway.

Since the mainline separates in this option and both the eastbound and westboundcarriageways have their own individual alignment the A14 mainline has beendesigned as two separate interchange links at a design speed of 85kph. This hasresulted in lower radii curves being used in the alignment producing a compactlayout in accordance with standards.

From the A1 crossing the A14 mainline runs east and passes to the north of theBuckden North Landfill Site before crossing the River Great Ouse and its floodplainon a multi-span viaduct. The mainline continues in an easterly direction across theEast Coast Mainline railway north of the Wood Green Animal Shelter. It thenpasses to the south of Fenstanton and the Conington Landfill Site prior to rejoiningthe existing A14 mainline to the south of Fen Drayton. In doing so the followinglocal roads require to be bridged:

After tying into the existing A14 the proposed mainline comprises online wideningof the existing A14 corridor as far as Lolworth Spring, west of Bar Hill. BetweenTrinity Foot and Lolworth Spring the existing eastbound verge of the A14 containsBT fibre optic cables. As a result of this, together with the need for access to bemaintained to properties on the north side of the A14, the existing road has beenwidened to the south. From Lolworth Spring, the proposed mainline moves offlineto the north of Bar Hill by approximately 110 metres at its maximum point in orderthat a high capacity junction can be constructed to replace the existing junction.After passing Bar Hill the route option requires an extra lane as a result ofincreased traffic volumes accessing the A14 at Bar Hill. It therefore continuesoffline to the west of Girton at the M11 Junction 14 as a Dual 4 Lane All Purpose(D4AP) road.

To the east of Girton the Blue Route Option continues as online widening along theCambridge Northern Bypass to Fen Ditton. From the M11 Junction 14 through theHiston and Milton Junctions to Fen Ditton Junction off-slip the CNB is upgraded toD3AP standard. As a result of traffic volumes a fourth 'auxiliary lane' has beenadded between the merges and diverges between the M11 Junction 14 and MiltonJunction.

With the construction of the improved A14 it is proposed that the existing A14 willbe detrunked between Spittals Junction and Fen Drayton. Included in thisdetrunking works would be the removal of the Huntingdon Railway Viaduct and therealignment of the existing A14 to form an at-grade staggered junction with theB1514, Brampton Road.

4.2.2 Junctions

JUNCTION STRATEGY A

Junction Strategy A has been developed following analysis of the A14 traffic model.It consists of three interchanges, namely Brampton, Fen Drayton and Girton, fourmainline junctions, Bar Hill, Histon, Milton and Fen Ditton and two Local AccessRoad junctions, Trinity Foot and Dry Drayton. These are described below in theorder that they appear along the A14 in a west to east direction together withdetails of the associated Local Access Road (LAR) layout.

Local Access Road

It is proposed that when the A14 improvement scheme is constructed the existingA14 will be maintained for use by local traffic. However, where the proposedmainline utilises the route of the existing A14 a designated Local Access Road(LAR) will be constructed in order to maintain the local road network. The LARlayout has been developed based on traffic flows taken from the A14 traffic modeland influenced by the layout of the Fen Drayton Interchange. It is shown ondrawing numbers 5021044/DR/HW/230 to 232.

Traffic figures indicate that an S2 standard LAR is required between Fen DraytonInterchange and Trinity Foot LAR Junction as well as between Trinity Foot Junctionand Girton Interchange. The layout of Fen Drayton Interchange splits the LAR sothat the eastbound and westbound carriageways run on opposite sides of the A14mainline. This means that the S2 LAR eastbound carriageway runs along theexisting A14 eastbound carriageway to Trinity Foot (to avoid the BT fibre opticcables) and the S2 westbound carriageway runs adjacent to the south of the A14mainline.

To the east of Trinity Foot Junction the LAR continues towards Bar Hill on thesouthern side of the proposed mainline. On approaching Bar Hill the LAR mergeswith the existing A14 westbound carriageway at the point where the proposed A14mainline moves offline and continues along the existing westbound carriageway tothe M11 Junction 14 via Bar Hill and Dry Drayton Junctions. At the M11 Junction 14it passes over the A14 westbound Link, under the A14 mainline and over both theA428 Links before tying into Huntingdon Road.

A1 Brampton Interchange

The proposed interchange arrangement, shown on drawing number5021044/DR/HW/202, involves a restricted movement option that links the existingA1 Southbound carriageway with the proposed A14 Eastbound carriageway andthe proposed A14 Westbound carriageway with the existing A1 Northbound andSouthbound carriageways. On joining the proposed A14, the A1 Southbound toA14 Eastbound Link does not merge into the mainline, instead it becomes a lanegain, converting the A14 from a D2AP carriageway to a D3AP carriageway east ofthe A1. Similarly, the A14 Westbound carriageway experiences a lane drop wherethe A14 Westbound to A1 Northbound/Southbound Link leaves the mainline,reducing the westbound carriageway of the A14 from a D3AP to a D2AP.

The proposed A14 Westbound to A1 Northbound Link crosses over the existing A1mainline and passes under the proposed A14 before tying into the A1 Northboundcarriageway just north of the Brampton-Grafham Road structure. The result ofwhich is the need for a new structure to maintain the local road over the A1 and thedemolition of a cottage with frontage onto the A1.

Also requiring demolition is a filling station that is affected by the realignment ofBuckden Road. In order to lift the local road over the mainline it must be takenoffline as shown on drawing number 5021044/DR/HW/202.

The location at which the proposed A14 crosses the existing A1 means thatBrampton Interchange is situated in close proximity to the existing A1/A14 Junctionat Brampton Hut. Therefore to accommodate any potential weaving issues on thestretch of the A1 between these two junctions an additional lane has been added tothe existing A1 between Brampton Hut and Buckden on both the Northbound andSouthbound carriageways.

Fen Drayton Interchange

The proposed interchange arrangement is shown on drawing number5021044/DR/HW/209 and involves a two-level, restricted movement interchangethat links the proposed A14 mainline with the local road network just to the west ofwhere the proposed A14 ties into the existing A14. The interchange allows thefollowing traffic movements:

All other movements, for example A14 Eastbound to LAR Westbound, can bemade by using the Trinity Foot LAR Junction which is situated approximately 1 kmeast of the Fen Drayton Interchange.

The location at which it is proposed to site the Fen Drayton Interchange sees theproposed A14 mainline on an embankment of between 2 - 3 metres in order thatthe road sits above the maximum flood level of a floodplain in the area. The impacton the interchange involves the vertical alignment having to be designed so that itcrosses over the A14. This produces a design that requires large amounts of fillmaterial to construct embankments that reach 10 metres in places.

Trinity Foot LAR Junction

Trinity Foot Junction is comprised of two roundabouts, one either side of theproposed A14, connected by a link that crosses mainline. The northern roundaboutis located to the west of Buckingway Business Park, north of the existing TrinityFoot Public House (Refer to drawing number 5021044/DR/HW/230). This is linkedto the existing Boxworth Road roundabout on the south of the A14 mainline by aD2AP standard road. The northern roundabout consists of four arms, one of whichis the link to the southern roundabout. The other three consist of the LAR from thewest, the realigned Buckingway Road from the north and another LAR to the eastaccessing properties on the north side of the A14.

The Blue and Orange Route Options have the D2AP westbound LAR carriagewaycoming off the dumbbell link to the south of the mainline. There is no designatedright turn lane on the link to provide access to the westbound carriageway for trafficcoming from the north and over the mainline, as this would involve widening thejunction structure considerably. Instead traffic will continue on the junction link fromthe north and use the southern dumbbell roundabout to double back to access thewestbound carriageway of the LAR.

Bar Hill Junction

The proposed junction, shown on drawing number 5021044/DR/HW/231, involvesa two bridge roundabout layout situated over the offline section of the A14 to thenorth of the existing junction. This allows the proposed LAR to run to the south ofthe mainline along the existing A14 and prevents local traffic from conflicting withtraffic in Bar Hill.

This option provides access to the B1050 Longstanton Road to the north, and to adual carriageway link to a new roundabout serving the local link road to the south.A short length of dual carriageway is also provided between this local linkroundabout and the existing Bar Hill roundabout, which would be retained in itspresent form. These sections of dual carriageway are necessary to cater foranticipated growth in traffic volumes arising from the proposed development atNorthstowe.

As a result of this development the major traffic flow through the junction will bebetween Cambridge and Northstowe and vice versa. Therefore in order to relievethe junction of the predicted high traffic flows generated by the development adesignated link and designated lane between Hatton's Road and the A14 mainlineand junction slip roads has been included within the junction layout.

The single lane link road to carry traffic between the A14 westbound carriagewayand Hatton's Road, diverges from the proposed A14 mainline westboundcarriageway and crosses over the link road between the junction roundabout andthe LAR roundabout. It then proceeds on a curve across the junction's west facingslips and the D3AP mainline before tying into Hatton's Road to the north.

Traffic flowing in the reverse direction will be segregated from Bar Hill Junction by adesignated lane between the realigned Hatton's Road southbound carriageway andthe junction's eastbound on slip.

Dry Drayton LAR Junction

The proposed A14 mainline alignment completely removes the existing junction atDry Drayton (Refer to drawing number 5021044/DR/HW/232). The displacement ofthe A14 mainline to the north of its existing alignment necessitates a new DryDrayton Junction.

The junction consists of a four armed roundabout to the south of the A14 allowingtraffic to access Oakington Road and Dry Drayton Road from the west to eastrunning LAR and vice versa. Access from the A14 mainline to Dry Drayton in thesouth and Oakington in the north will be available via the LAR connection at BarHill.

M11 Junction 14

M11 Junction 14 is a strategic interchange that links three major routes with freeflow movement. It routes traffic from the M11 motorway and the CambridgeNorthern Bypass onto the A14. The existing interchange incorporates a number offeatures that are undesirable for the level of strategic traffic carried.

The following geometric and operational deficiencies are built into the currentlayout:

The proposed junction, shown on drawing number 5021044/DR/HW/232, uses theexisting links and slip roads as much as possible and retains the existing bridges.This provides a compact design at minimal cost and environmental impact.

The junction design provides an improved strategic traffic movement for the A14eastbound to A14 westbound, which is currently achieved by a tight radius loop.This loop is removed and replaced with an interchange link, designed to a higherdesign speed than the existing. By removing this existing loop the weavingproblems created between the existing diverge, from the M11 northbound to theA14 eastbound are eliminated.

The design of the A14 eastbound to A14 westbound interchange link requires therealignment of the A428 to A14 eastbound link. The link merges the major A14eastbound traffic on the slow side thus eliminating the problem of turbulencediscussed above.

The A14 westbound to A14 eastbound interchange link is aligned along the existinglink until just after the u-turn for the crematorium. After the u-turn (removed in thisdesign) it moves slightly to the north in a greenfield site where the link crosses theA428 to A14E and merges with it on the right hand side.

No change is envisaged to the A14 eastbound to M11 slip road.

Another important aspect this option achieves is the segregation of long distancestrategic traffic from the local traffic. The current A1307 LAR, which is dualcarriageway, directly links into the A14 traffic. These links have been removed inthis design and replaced with a single carriageway road that utilises the currentLAR westbound alignment. The new alignment utilises the existing HuntingdonRoad Bridge and the LAR is segregated from the A14 mainline and aligned to thesouth.

Histon Junction

The existing two overbridges and County Road gyratory above the A14 at Histonare not directly affected by the Cambridge Northern Bypass improvements.

Milton Junction

The existing two overbridges and County Road gyratory above the A14 at Miltonare not directly affected by the Cambridge Northern Bypass improvements.

Fen Ditton Junction

The proposal retains the existing half diamond junction with the slip roads beingredesigned to accommodate predicted traffic flows.

JUNCTION STRATEGY B (LIMITED JUNCTION OPTION)

Junction Strategy B, known as the Limited Junction Option (LJO), has beendeveloped in order to minimise the number of locations where local traffic canaccess the A14. This allows the A14 to primarily become a strategic traffic route.

As with Junction Strategy A, Strategy B consists of three interchanges, namelyBrampton, Fen Drayton and Girton. However, there are only three mainlinejunctions, located at Histon, Milton and Fen Ditton and three Local Access Roadjunctions, Trinity Foot, Bar Hill and Dry Drayton. The only junctions, however, thatdiffer to those described for Junction Strategy A are Bar Hill Junction, Dry DraytonJunction and Girton Interchange. These are described below in the order that theyappear along the A14 in a west to east direction together with details of theassociated Local Access Road (LAR) layout.

Local Access Road

As with Junction Strategy A, the LAR layout has been developed through theanalysis of the A14 traffic model and influenced by the layout of the Fen DraytonInterchange. This LAR is shown on drawing numbers 5021044/DR/HW/230 and240 to 241.

Between Fen Drayton Interchange and Bar Hill the LAR has the same layout asdescribed in Section 4.2.2 for Junction Strategy A. At Bar Hill Junction there is noaccess to or from the A14 therefore the LAR returns to a D2AP at this point toaccommodate the high volumes of traffic that will use the LAR between Cambridgeand Northstowe. To reflect this on the A14 the mainline remains as a D3AP throughBar Hill to M11 Junction 14.

At Bar Hill the LAR splits into two separate carriageways, with the eastboundcarriageway running adjacent to the A14 mainline and the westbound carriagewaycontinuing along the existing A14 westbound carriageway. The LAR continuesunder this arrangement until the two carriageways join back together before tyinginto Huntingdon Road.

Bar Hill LAR Junction

The Bar Hill Limited Junction Option, as shown on drawing number5021044/DR/HW/240, consists of a dumbbell roundabout layout linking Bar Hill andthe proposed Northstowe development with the LAR network. There is no accessto or from the proposed A14 mainline. The S2 LAR that runs to the west of Bar Hillties into the southern dumbbell roundabout, which is linked to both the existing BarHill roundabout to the south and the second dumbbell roundabout to the north by aD2AP standard link road. As well as this link the northern roundabout also has therealigned S2 Hatton's Road and eastbound carriageway of the Bar Hill to Girtonsection of the LAR tying into it.

As with the Junction Strategy A, the major traffic flow at this junction will bebetween Cambridge and the proposed Northstowe development except that trafficwill be on the LAR rather than the mainline. Therefore to avoid feeding these flowsthrough the LAR junction two designated links have been included in the junctionlayout. The westbound link has the same geometry and is very similar in its route tothat described in the Junction Strategy A section. The westbound carriageway ofthe D2AP LAR splits on the approach to Bar Hill with the LAR continuing through tothe southern dumbbell roundabout and the designated link crossing over thedumbbell link and the A14 mainline before tying into Hatton's Road. Under theproposals of the Northstowe development Hatton's Road is proposed to beupgraded to D2AP standard, therefore the link will merge with Hatton's Road as alane gain to coincide with these proposals.

Similarly, to divert traffic travelling from Northstowe to Cambridge away from thejunction itself a designated left turn link has been provided between Hatton's Roadand the eastbound carriageway of the LAR. To tie-in with the proposals for Hatton'sRoad this link diverges from Hatton's Road as a lane drop leaving an S2carriageway running into the northern dumbbell. The link then acts as a lane gainon the eastbound carriageway of the LAR where it merges with the LAR as itleaves the northern dumbbell.

Dry Drayton LAR Junction

As with the junction option for Junction Strategy A the Dry Drayton LJO is an LARjunction. As drawing number 5021044/DR/HW/241 shows the junction spans theD3AP mainline and the split D2AP LAR. Connection between Oakington Road/DryDrayton Road and the LAR is provided via a dumbbell layout, which is linked to leftin/left out junctions with the LAR.

M11 Junction 14

The layout of M11 Junction 14 associated with the LJO (Refer to drawing no.5021044/DR/HW/241) is intended to perform the same function as the option forthe previous junction strategy in that it utilises the existing corridors of theinterchange links and slip roads as much as possible and retains the existingbridges.

However the LJO layout provides linkage between the D2AP LAR/HuntingdonRoad and the trunk road/motorway network whereas the Junction Strategy A runsthe S2 LAR directly through the junction into A1307 Huntingdon Road with noconnection. The provision of LAR links to the original junction option layout createsan additional six link roads within the junction. The most significant of the twelvemerging and diverging movements introduced by these links are those interfacingwith the trunk road/motorway network, as listed below:

4.2.3 Structures

EXISTING STRUCTURES

Existing structures along the scheme have been discussed in Section 2.5. Tables4.2 and 4.3 of Appendix B list those structures affected by the Blue Route Optionand makes recommendations as to their treatment under this project.

NEW STRUCTURES

In carrying out the preliminary design of new structures, the identified structures,where appropriate, have been grouped by structural type. For each group, aconceptual design has been worked up, based on similar structures that have beenfound to be economic on other recent schemes.

The groups are shown on the following drawings:

Where space is available, open abutments (bankseats) have been shown, sincethey are generally considered to be more aesthetically attractive. Where space isrestricted, eg at junctions, closed (full height) abutments have been shown.

Steel composite construction has been assumed, since this has been found to bemore cost effective than concrete on recent schemes. However, concretesolutions, particularly precast concrete beams, will be equally technicallyacceptable.

It should be noted that the drawings show concepts and indicative details; nocalculations have been done to determine member sizes.

The major structure on this route option is the River Great Ouse Viaduct, whichcrosses the flood plain of the River Great Ouse. Details of this structure are shownon drawing numbers 5021044/DR/BR/008 and 009.

Tables 4.4 to 4.7 in Appendix C detail the number of new structures required for theBlue Route Option.

4.2.4 Relaxations and Departures From Standards

As a result of various constraints along the scheme corridor it has been necessarywhen designing the scheme to drop below desirable minimum standards in certainlocations, as permitted by the Highway Agency's Design Manual for Roads andBridges (DMRB).

The Blue Route Option mainline has been designed to standard without the need toincorporate any relaxations or Departures from Standards. However, a number ofsideroads and junctions along the route have been designed with substandardgeometry in order to minimise the impact on the surrounding area. In some of thesecases, where the geometry has had to be significantly reduced in standard, adeparture from standards has been applied for to the Highways Agency or localhighway authority for their approval. Table 4.8 in Appendix D details the Departuresfrom Standards for the Blue Route Option and provides a statement justifying theirinclusion in the scheme.

4.2.5 Earthworks

The alignment of the Blue Route Option begins by following the existing groundlevel on its approach to the A1 corridor before extensive earthworks in the form ofembankments are proposed as part of the A1 Brampton Interchange. Where thereare two A14 eastbound options for crossing the A1, it is the option that passesbeneath the A1 in cutting that is preferable in terms of earthworks, due to therebeing a shortfall of generated material along the scheme. However, it should benoted that other aspects of the design, for instance drainage and construction ofthe bridge under the A1 make this option less favourable.

From the A1 Brampton Interchange to the A1198 the main earthworks required arethe approach embankments to the River Great Ouse Crossing and the cuttingthrough the ridge to the south of Godmanchester. The Blue Route Option hasembankment heights of up to 13 metres at the River Great Ouse and cutting depthsof approximately 7-8 metres where the route intersects the A1198, masking it fromthe town of Godmanchester.

From the A1198 to the point where the route joins the existing A14 at Fen Drayton,the proposed route option generally follows the local topography requiring onlyminor cuttings and low embankments. The vertical alignments indicate that thedepth of these cuttings does not exceed 6 metres.

The low embankments referred to above have been deliberately designed into thescheme to ensure that the route runs above the flood levels of the localisedfloodplains along the A14 corridor. Fen Drayton Interchange is located on afloodplain and therefore requires embankments of up to 9 metres in order to lift thelink roads over the raised mainline.

It is the junctions and side roads within the Blue Route Option that constitute themajority of the fill required. This is because all the side roads cross above the A14mainline. For the more major side roads large sweeping alignments have beendesigned that have resulted in long lengths of embankment.

To the east of Fen Drayton Interchange the mainline mainly follows the route of theexisting A14 to Fen Ditton with the existing carriageway and earthworks beingwidened. The existing carriageway tends to follow the existing ground level with afew minor embankments and small cuttings in isolated locations. Therefore, theproposed mainline will not require any major online embankments until reachingthe CNB where widening of the existing 8 metre high embankments are required.Major earthworks are required for the numerous associated junctions, in particularthe designated Northstowe Links at Bar Hill and the M11 Junction 14 options. Alljunctions cross over the mainline and are therefore on embankment. The lack ofsite won material at this end of the scheme, as a result of there being few cuttings,means that fill material will have to be imported for the construction of the junctionembankments.

The only significant cutting in the eastern end of the scheme is where the A428eastbound carriageway is realigned to tie into the Cambridge Northern Bypass.Approximately 750 metres of the link is situated in a cutting of some 4 metresdepth.

Drawing numbers 5021044/DR/HW/202, 203, 205 to 207, 209, 230 to 234 and 240to 241 provide details of the heights of the earthworks required along the schemeand Table 4.1 in Appendix A schedules the volume of cut and fill for all the schemeroute options. Drawing numbers 5021044/DR/HW/301 & 302 show typical crosssectionstaken through the various route options and provide an indication of thescale of the major earthworks.

4.2.6 Contaminated Land

In addition to the landfill sites at Buckden, Conington and Milton, as discussed inSection 2.4.4, there are also several potential contaminated sites associated withboth former and existing petrol stations, fuel and goods distribution depots,scrapyards and vehicle repair garages.

South of Brampton village, to the north of the proposed Blue Route Optionalignment and the Buckden North landfill site a former petrol station is present.Although there is no visual evidence of contamination on the surface of the sitethere is a possibility that the associated underground fuel storage tanks may havehistorically leaked or discharged fuels into the underlying ground and groundwater.Therefore, as the realignment of Buckden Road impacts on this filling station thereis a possibility that the ground and groundwater beneath the route may be affectedby contaminant migration.

In the vicinity of the proposed Trinity Foot Junction a number of potentialcontaminated sites have been identified, including electroplating and metal finishingworkshops, existing and former petrol stations. The potential environmental issuesof these sites may impact on the proposed junction works at Trinity Foot and furtherinvestigation would be required at Trinity Foot prior to construction to verify if anycontamination is present which may impact upon the construction works or thescheme in the long-term.

Also within the area is an industrial estate south of Bar Hill, which contains anumber of industrial processes which may have led to contamination entering theunderlying geology and groundwater regimes. Activities include an operationalpetrol filling station, transformer manufacture, printers and glass fibre manufacture.

The industrial estate lies to the south of the existing A14 and with off-line wideningto the north being the favoured option it is unlikely that any ground contaminationwill be encountered along this northern route by the proposed road construction.

To the east of the scheme there are areas to the east and south of Milton Junctionassociated with activities such as vehicle repair, scientific apparatus andinstrumentation manufacture, pharmaceutical manufacturers and distributors. Tothe north and east of Milton junction there are enamelling and sheet metal works,garage services, printers, cleaning services, hydraulic equipment servicing andscientific apparatus and instrumentation manufacture.

None of the above sites lie beneath the proposed construction route of the existingA14, and contaminant migration is likely to be minimal due to the underlyinggeology consisting predominantly of cohesive materials or clays. However, an oldrailway yard and part of the existing sewage treatment works historically underliethe existing A14 / Cambridge Northern Bypass prior to its construction. Thereforefurther widening of the A14 / Cambridge Northern Bypass may encounter potentialcontamination associated with these former uses.

4.2.7 Public Utilities

As the Blue Route Option travels from west to east the first major conflict withStatutory Undertakers' (SU) apparatus is an oil pipeline that runs in a north to southdirection parallel with the A1. Due to the angle at which the route option crossesthe pipeline it is likely that a diversion will be required rather than just theimplementation of protection measures.

East of the oil pipeline there are minor conflicts with SU apparatus (mainly watermains) where the local road network requires realigning in order to cross themainline. The next major impact occurs with BT fibre optic cables, which run in theexisting A14 eastbound verge between Fenstanton and Bar Hill. The proposed A14Eastbound to LAR Eastbound Link of the Fen Drayton Interchange crosses thisapparatus in two places as does the proposed A14 mainline as it moves offline atLolworth Spring to the north of Bar Hill.

In the same location but in the existing A14 westbound verge are 300mm diameterpotable water mains. As a result of widening this section of the existing A14 to thesouth these mains require diverting. A number of 6" and 8" gas mains are alsoaffected where they cross the mainline at Trinity Foot and Bar Hill. Foul seweragepipes that run from the Huttons Drove Sewage Treatment Works, between TrinityFoot and Bar Hill, across the existing A14 require rerouting as a result of the BlueRoute Option.

At the eastern end of the scheme the CNB was originally constructed largelythrough a green field site where disturbance to utilities was minimal. ExistingStatutory Undertakers' plant tends to cross the CNB radially into Cambridge andcrosses above the A14 in bridge decks at Histon and Milton junctions. Thesebridges, and hence the plant, are not directly affected by the Blue Route Optionproposals.

However one main, a 200mm diameter gas main running for 1,600 metreslongitudinally in the north verge of the embankment at Girton, is directly affected.Furthermore a 180mm polyethylene gas main and a cluster of minor servicescrossing in the Girton Road overbridge deck are affected as this bridge deck isrequired to be replaced.

The impact in terms of cost that each route option has on the StatutoryUndertakers' apparatus is listed in Table 4.1 in Appendix A.

4.3 Purple Route Option

4.3.1 Mainline Alignment

As can be seen on drawing numbers 5021044/DR/HW/210 to 218, and 230 to 234the alignment of the Purple Route Option matches that of the Blue Route Option upto a point between the A1198 and Moat's Way. From here it runs in a north easterlydirection before tying into the existing A14 to the west of Gore Tree Farm where itcontinues to run online through Fenstanton to Fen Drayton and on to Fen Ditton.

The online section of the route option consists of asymmetrical widening to thenorth in order to avoid properties on the fringes of the southern side of the existingA14 between Gore Tree Farm and Galley Hill. By widening to the north a Site ofSpecific Scientific Interest located to the east of Gore Tree Farm is also avoided asare BT fibre optic cables situated in the existing A14 southern verge.

Between Galley Hill Junction and Fen Drayton the existing A14 is widenedasymmetrically to the south, enabling the existing local road network to be utilisedfor local traffic between Galley Hill and Fenstanton whilst at the same time avoidingthe conservation area within Fenstanton. However, it does result in the loss of fourhouses, disused farm outbuildings and a BT Feeder Station along the route. It alsorequires some substantial diversion works of Statutory Undertakers' apparatus(refer to Section 4.3.7).

In order to separate the local traffic from the strategic traffic on the proposed A14, aSingle 2 Way (S2) Local Access Road (LAR) has been provided. The LAR utilisesthe existing section of the A14 between Huntingdon and Gore Tree Farm, which ismade redundant by taking the proposed A14 offline. At Galley Hill the LAR is linkedinto the proposed Galley Hill Junction before proceeding on the route of the existingaccess road to the west of Fenstanton. It continues adjacent to the mainline alongthe boundary of the Fenstanton conservation area where it merges withFenstanton's original bypass. This avoids directing local through traffic along thevillage's narrow high street. From Fenstanton the LAR runs adjacent to thewidened A14 on the eastbound carriageway of the existing A14.

With the construction of the improved A14 it is proposed that the existing A14 willbe detrunked between Spittals Junction and Hemingford Grey. Included in thisdetrunking works would be the removal of the Huntingdon Railway Viaduct and therealignment of the existing A14 to form an at-grade staggered junction with theB1514, Brampton Road.

4.3.2 Junctions

Following the analysis of the A14 traffic model only one junction strategy wasdeemed viable for the Purple Route Option. The strategy consists of twointerchanges, namely Brampton and M1 Junction 14, five mainline junctions, GalleyHill, Bar Hill, Histon, Milton and Fen Ditton and two Local Access Road junctions,Trinity Foot and Dry Drayton.

With the exception of Galley Hill Junction, the junctions listed above are the sameas those described for the Blue Route Option Junction Strategy A in Section 4.2.2.Galley Hill Junction is described below.

JUNCTION LAYOUT
Galley Hill Junction

The proposed junction arrangement situated in the same area as the existingGalley Hill Junction and shown on drawing number 5021044/DR/HW/217,comprises a two-bridge, grade separated, large radius roundabout allowing allmovements to and from the A14 mainline. The roundabout contains nine arms, fourof which are the westbound and eastbound on and off slip roads. The remainingarms connect into the local road network including the B1096 St Ives Road to thenorth and the B1040 to the south. There is access to the LAR located on thesection of existing A14 that has been made redundant by taking the mainlineoffline, as well to the recently levelled development area to the south east of thejunction.

The location of the proposed junction is very confined, with property and landconstraints affecting the layout of the junction. As a consequence retainingmeasures will be required in order that the junction slip roads can run in closeproximity to the mainline and allow a compact layout. A retaining measure will alsobe required to avoid a mobile phone mast and station. To the north-west of thejunction the LAR impacts on the nearby Galley Hill farm, where a farm house andsome disused outbuildings would require demolition.

4.3.3 Structures

EXISTING STRUCTURES

Existing structures along the scheme have been discussed in Section 2.5. Tables4.2 and 4.3 of Appendix B list those structures affected by the Purple Route Optionand makes recommendations as to their treatment under this project.

NEW STRUCTURES

The major structure on the Purple Route Option is the River Great Ouse Viaduct,which crosses the floodplain of the River Great Ouse as shown on drawing number5021044/DR/BR/008. For further details of new structures refer to Section 4.2.3.

4.3.4 Relaxations and Departures From Standards

The Purple Route Option mainline runs primarily on the line of the existing A14,therefore a series of relaxations from standard have been incorporated into thedesign in order to minimise the impact on nearby properties.

A number of sideroads and junctions along the route have been designed withsubstandard geometry to affect as little of the surrounding area as possible. Insome of these cases, where the geometry has had to be significantly reduced instandard, a departure from standards has been applied for to the Highways Agencyor local highway authority for their approval. Table 4.8 in Appendix D details theDepartures from Standards for the Purple Route Option and provides a statementjustifying their inclusion in the scheme.

4.3.5 Earthworks

As the Purple Route Option follows the existing A14 alignment there is very littleneed for any major earthworks on the online section as it tends to follow the localtopography. The exception to this is in isolated areas where the road climbs onembankment to rise above localised floodplains.

The commonality between this route option and the Blue Route Option means thatthere is a 9 metre deep cutting to the east of the A1198 between chainages 10000and 11150. This is to mask the route from the town of Godmanchester and toenable fill material to be generated.

It is the junctions and side roads within the Purple Route Option that require themajority of the fill material. This is because all the side roads cross above the A14mainline. For the more major side roads large sweeping alignments have beendesigned that have resulted in long lengths of embankment. However, the PurpleRoute Option has the lowest earthworks imbalance of the route options as a resultof having fewer side road crossings.

4.3.6 Contaminated Land

For details of contaminated land refer to Section 4.2.6.

4.3.7 Public Utilities

The Purple Route Option affects the same Statutory Undertakers' apparatus as theBlue Route Option with the exception of the gas mains to the south of Fenstanton.By widening the existing A14 to the south when coming online, fibre optic cables inthe existing A14 westbound verge between Galley Hill and Fenstanton aredisrupted and require diverting. A BT feeder station requires demolishing to thesouth of Fenstanton as a result of the widening, which also impacts onapproximately 2.5km of water main.

The impact in terms of cost that each route option has on the StatutoryUndertakers' apparatus is listed in Table 4.1 in Appendix A.

4.4 Orange Route Option

4.4.1 Mainline Alignment

The alignment details of the Orange Route Option are shown on drawing numbers5021044/DR/HW/222, 224 to 226, 228, 230 to 234 and 240 to 241. As shown onthe drawings the proposed Dual 2 Lane All Purpose (D2AP) A14 mainline leavesthe existing A14 corridor to the west of Brampton Hut Junction and heads south,adjacent to the west of the A1 before crossing it further south than the Blue andPurple Route Options.

On leaving the A1 A1 Brampton Interchange the Orange Route Option passes tothe south of the Buckden South Landfill Site before crossing the River Great Ouseand its floodplain and the East Coast Mainline railway on a multi-span viaduct. TheD3AP mainline continues in an easterly direction passing to the south of the WoodGreen Animal Shelter. In doing so it crosses a number of local roads, which arelisted below:

This route option then passes approximately 1.5km to the north of the village ofHilton before continuing eastwards to the site of the Fen Drayton Interchange.From this point it continues to Fen Ditton along the same alignment as the BlueRoute Option.

With the construction of the improved A14 it is proposed that the existing A14 willbe detrunked between Spittals Junction and Fen Drayton. Included in thisdetrunking works would be the removal of the Huntingdon Railway Viaduct and therealignment of the existing A14 to form an at-grade staggered junction with theB1514, Brampton Road.

4.4.2 Junctions

The Orange Route Option has two junction strategies, both of which are almostidentical to those described for the Blue Route Option. The difference between thetwo strategies is the location of the A1 Brampton Interchange, which is describedbelow for the Orange Route Option. For details of the other junctions refer toSection 4.2.2.

A1 BRAMPTON INTERCHANGE

The layout of Brampton Interchange for the Orange Route Option is similar to thatof the Blue Route Option in that the same restricted movements are provided for.The existing A1 Southbound carriageway is linked with the proposed A14Eastbound carriageway and the proposed A14 Westbound carriageway has links tothe existing A1 Northbound and Southbound carriageways. The proposed A14Westbound to A1 Northbound Link crosses over the existing A1 mainline andpasses under the proposed A14 before tying into the A1 Northbound carriagewayat the existing Brampton-Grafham Road structure. By taking the A14 mainlinefurther south and locating the interchange further south, this link is tied into theexisting A1 Northbound carriageway and can be accommodated by the existingstructure.

The vertical alignment of the A14 Westbound to A1 Northbound Link requires substandardvertical geometry in order for it to pass under Brampton Road and overthe A1 before passing beneath the proposed A14. This is discussed in more detailin Section 4.4.4.

As with the Blue and Purple Route Options the location at which the proposed A14crosses the existing A1 means that Brampton Interchange is situated in closeproximity to the existing A1/A14 Junction at Brampton Hut. Therefore, an additionallane has been added to the existing A1 between Brampton Hut and Buckden onboth the Northbound and Southbound carriageways to accommodate weaving.

4.4.3 Structures

EXISTING STRUCTURES

Existing structures along the scheme have been discussed in Section 2.5. Tables4.2 and 4.3 of Appendix B list those structures affected by the Blue Route Optionand make recommendations as to their treatment under this project.

NEW STRUCTURES

The major structure on the Orange Route Option is the River Great Ouse Viaduct,which crosses both the floodplain of the River Great Ouse and the adjacent runningEast Coast Mainline (ECML) railway as shown on drawing number5021044/DR/BR/004. For further details of new structures refer to Section 4.2.3.

4.4.4 Relaxations and Departures From Standards

As with the Blue Route Option the Orange Route Option mainline has beendesigned without the need for any relaxations or Departures from Standards.Relaxations were however required in the design of Fen Drayton Interchange aswell as in the realignment of some of the existing roads in order that they could betaken across the proposed A14 mainline.

The vertical alignment of the A14 Westbound to A1 Northbound Link has a numberof constraints along its alignment that were required to be taken into account whendesigning the link. In order to avoid these constraints the geometry has had to besignificantly reduced in standard and a departure from standards has been appliedfor to the Highways Agency for their approval. Table 4.10 in Appendix D lists anddetails the departures from standards for the Orange Route Option as well asproviding a statement justifying their inclusion in the scheme.

4.4.5 Earthworks

The alignment of the Orange Route Option begins by following the existing groundlevel on its approach to the A1 corridor before extensive earthworks in the form ofembankments are proposed as part of the A1 Brampton Interchange.

From the A1 Brampton Interchange to Fen Drayton the main earthworks requiredare the approach embankments to the River Great Ouse/ECML Crossing, whichreach heights of approximately 13 metres, and the cutting through the ridge to thesouth of Wood Green Animal Shelter, which has a maximum depth of 8 metres.The Orange Route Option also has a pronounced cutting between Offord Road andSilver Street, approximately 2 km in length and up to 11 metres in depth.

From Silver Street to the point where the route joins the existing A14 at FenDrayton, the proposed route option generally follows the local topography requiringonly minor cuttings and low embankments. The low embankments referred toabove have been deliberately designed into the scheme to ensure that the routeruns above the flood levels of the localised floodplains along the A14 corridor. FenDrayton Interchange is located on a floodplain and therefore requiresembankments of up to 9 metres in order to lift the link roads over the raisedmainline.

From Fen Drayton to Fen Ditton the Orange Route Option has the same alignmentas the Blue Route Option and hence the same earthworks. These are described inSection 4.2.5.

As with the Blue and Purple Route Options there is an overall shortfall of materialgenerated along the route as a result of the number of sideroads that cross themainline on embankment. However, the greater number of cuttings along theOrange Route does mean that it has a lower imbalance of material compared withthe Blue Route Option. This is shown in Table 4.1 of Appendix A.

4.4.6 Public Utilities

The public utilities affected by the Orange Route Option are very similar to thosedescribed for the Blue Route Option. The first main conflict occurs with an oilpipeline that runs in a north to south direction parallel with the A1. The angle atwhich the route option crosses the pipeline requires a diversion of the pipelinerather than just the implementation of protection measures.

Minor conflicts with SU apparatus (mainly water mains) on the local road networkare present where the sideroad is realigned to cross the mainline. The next majorimpact occurs where the mainline ties back into the existing A14 corridor havingrun offline from Brampton Hut. Conflicts with BT fibre optic cables, water mains andgas mains occur where the proposed route impacts on the existing verges.Reference should be made to Section 4.2.7 regarding these conflicts as they areidentical to those described for the Blue Route Option.

The impact in terms of cost that each route option has on Statutory Undertakers'apparatus is listed in Table 4.1 in Appendix A.

4. Engineering Assessment

5. Environmental Assessment - 1

5.1 Introduction

An environmental assessment has been undertaken of the route options beingconsidered for the improvement of the existing A14 from Ellington to Fen Ditton.The aim being to:

identify the environmental advantages, disadvantages and constraints associated with each of these route options; andallow the public and statutory environmental bodies to comment on their implications.lead to the selection of a preferred scheme.


5. Environmental Assessment - 1

5. Environmental Assessment - 2

5.2.1 Legislative Background

The Environmental Impact Assessment (EIA) for this scheme has been prepared inaccordance with the requirements of the Highways (Assessment of EnvironmentalEffects) Regulations 1999 (SI No. 369) under the Highways Act 1980. TheseRegulations implement the European Community Directive 85/337/EEC asamended by Directive 97/11/EC.

The EIA describes the main effects of the scheme proposals on both the man-madeand natural environment and the measures taken to reduce adverse effects.Specialist technical reports have been prepared on a variety of environmentaltopics, these are included in the Environmental Assessment Report (EAR).

5.2.2 Methodologies

Guidance for undertaking the environmental assessment of major highwaysschemes is provided in the Highways Agency publication the 'Design Manual forRoads and Bridges' (DMRB), 'Volume 11: Environmental Assessment', includingupdates. Volumes 5 and 10 of the DMRB are also relevant.

The DMRB methodology is intended to provide environmental assessment that is inaccordance with the Highways (Assessment of Environmental Effects) Regulations1999, for schemes promoted under The Highways Act. Section 195 A(2) of the Actrequires:

The DMRB guidance is the principal guidance used for the evaluation of allenvironmental effects associated with this scheme, whether attributable to the newtrunk road or to consequent changes to the local road network. The environmentaldata from this assessment process is then also used to generate environmentalinputs to the scheme appraisal and some of the appraisal data can expand thecoverage of the environmental assessment, as noted below.

For technical appraisal of the project as part of the process of approving thefunding, the guidance to follow is TAG, the Department of Transport's detailedguidance on the appraisal of transport projects. This updates the previous DETRpublication 'Guidance on the Methodology for Multi-Modal Studies' (GOMMMS)(March 2000), as interpreted by the DETR & HA document 'Applying the Multi-Modal New Approach to Appraisal to Highway Schemes' (the 'Bridging Document')(March 2001). In TAG there are two broad levels of appraisal 'strategy' or 'plan',the level of reporting for this project will be at 'plan' level - previous appraisal workunder CHUMMS was to 'strategy' level.

Most of the environmental data for the scheme appraisal will be provided from theDMRB-based study. However, the TAG approach varies in its scope and analysisfrom DMRB for some topics; this additional data is also reported on in the EAR.The Scoping Report indicated where there would be material included beyond thatcovered by the DMRB.


5. Environmental Assessment - 2

5. Environmental Assessment - 3

5.3 Approach to Environmental Assessment

5.3.1 Environmental Topics

The EIA addresses all potentially significant environmental impacts. Theseencompass the following topics, each of which is also covered by a separatechapter in this environmental assessment:

5.3.2 Study Area

For each of the topics, a study area has been selected which reflects the area overwhich changes to the environment are likely to occur as a result of the scheme. Acorridor, wider than the limits of the land likely to be used or acquired, will beassessed and will vary depending on the environmental resources underconsideration.

5.3.3 Baseline Condition

Desk studies, supplemented by additional surveys and consultation, has been usedto compile a picture of the current (2003/04) environmental conditions.The general approach reviews the various surveys undertaken previously,determines their validity for use as part of this environmental assessment andmakes recommendations for an ongoing strategy for updating existing surveys orcarrying out new additional surveys.

5.3.4 Receptors and their Sensitivity

Receptors are defined as the physical resource or user group that will experiencean impact. The baseline studies are used to identify potential environmentalreceptors. Some are more sensitive to change than others. This sensitivity may beinfluenced by factors such as:

5.3.5 Types of Impact

Impacts are defined as the results of physical changes to the environment or trafficflows attributable to the construction and operation of the highway scheme. Theyreflect the magnitude of the effect on the environment and the sensitivity of theenvironment.

Impacts may be beneficial or adverse, and may also be categorised as:

5.3.6 Temporal Scope

In considering the impact of a highway scheme it is necessary to identify impactswhich may occur during the construction and operational phases, including theimpact of any maintenance activities.

The construction phase extends from the commencement of site works to theopening of the scheme. Assumptions will be made about the duration of theconstruction programme and the key activities which will be involved.

The operational phase extends from the opening of the scheme to its maximumutilisation. It is recognised that some aspects of the environment are constantlychanging and that some environmental design measures will take time to becomeestablished and effective. The assessment will therefore consider operationalphase impacts in the Opening Year (2010) and the Design Year (2025), takingmitigation measures into account.

5.3.7 Magnitude of Effects

The magnitude of effects will be assessed against a defined hierarchy of scale andwill be specific to each topic.

5.3.8 Significance of Impacts

The magnitude of an effect does not translate directly into its significance as animpact. For example, a significant impact may result from a relatively minor effecton a resource of national value or as a result of a severe effect on a resource oflocal value. Assignment of significance will be undertaken in a consistent andsystematic manner through the establishment of a set of significance criteria foreach topic.

5.3.9 Mitigation Measures

Mitigation measures will seek to avoid adverse impacts or to minimise them suchthat their significance is reduced to an acceptable level.

Individual mitigation measures may address more than one impact, for exampleplanting may be used to reduce visual impact while also benefiting wildlife.Occasionally, measures which seek to mitigate one impact may have an adverseeffect on another topic area. At this stage, mitigation measures will necessarily bespecified only in outline.

The scheme options will be assessed on the basis that the stated mitigationmeasures are in place.

5.3.10 The Do-Minimum Scenario

The EIA will need to draw comparisons between the Do-Something and Do-Minimum scenarios in order to establish whether the scheme is worth implementingand whether the relative "environmental cost" can be justified. Often the Do-Minimum scenario will be detrimental in environmental terms. For example, risingtraffic levels on an existing road may result in high levels of air pollution at housesclose to the route.

In specifying the Do-Minimum scenario a number of transport networkimprovements will be considered:

Recognising the current doubtful integrity of the Huntingdon viaduct the Do-Minimum transport scenario will assume that the viaduct is replaced.

5.3.11 Environmental Design Strategy

Scheme specific environmental design objectives have been developed and are setout below. Developing an environmental design strategy at this stage is beneficialbecause it promotes close liaison between the scheme designers andenvironmental specialists, allowing key environmental objectives to be consideredwithin option design. It recognises that the study area contains a number ofsignificant environmental constraints, particularly related to the valley of the RiverGreat Ouse and the close proximity of existing and planned development at theeastern end of the route. On the other hand, improvements to the road networkoffer the opportunity to improve environmental conditions for people living close tothose sections of the existing route which will be relieved and, by reducingcongestion, improve air quality and journey ambience.

TRAFFIC NOISE AND VIBRATION
AIR QUALITY AND GREENHOUSE GASES
LANDSCAPE, TOWNSCAPE AND VISUAL ISSUES
BIODIVERSITY
HERITAGE
WATER
ACCESSIBILITY
JOURNEY AMBIENCE
GEOLOGY AND SOILS
LAND USE

This environmental assessment reports on the extent to which these objectiveshave been met by the design of the preferred scheme.


5. Environmental Assessment - 3

5. Environmental Assessment -4

5. Environmental Assessment (continued)

5.4 Environmental Topics

The following sections cover the baseline conditions, mitigations and the assessment of environmental effects for