Highways Agency

1. introduction

1. Introduction

1.1 Overview of Stage 2 Scheme Assessment Report Part I

The Stage 2 Scheme Assessment Report (SAR) Part I summarised all previous studies carried out under the current commission. It identified a number of factors to be considered when assessing the various alternative schemes that followed the proposals of the Cambridge to Huntingdon Multi Modal Study (CHUMMS). The report also identified the environmental, engineering, economic and traffic advantages and disadvantages and constraints associated with each of the alternative schemes.

1.2 Background and Objectives of Stage 2 Scheme Assessment Report Part II

Following the submission to the Highways Agency of the Stage 2 Scheme Assessment Report Part I in October 2004, an internal 'scheme challenge' was undertaken on the capital costs of the Orange Route Junction Strategy B together with development work on the proposed junction with the A14 and Brampton Road at Huntingdon. As well as this and as a result of ongoing reviews of the available routes, an alternative proposal that differs from the strategy proposed by CHUMMS was investigated. This proposal, shown on drawing number 5021044/DR/HW/106 in Volume II Part A, involves following the same layout and profile as the Orange Route Option with Junction Strategy B but replaces the Huntingdon Railway Viaduct in order to retain the existing A14 between Fen Drayton and the A1/A14 Hinchingbrooke Junction for traffic to and from the north. Traffic travelling to and from the west will use the new section of A14 between Ellington and Fen Drayton.

The objective of this addendum to the October 2004 Stage 2 Scheme Assessment Report (SAR Part I) is firstly to describe the alternative option (herein referred to as the Alternative Proposal) from an environmental, engineering, economic and traffic perspective, and identify the advantages, disadvantages and constraints associated with it. It also serves to update the appraisal of the Orange Route Option with Junction Strategy B (herein referred to as the CHUMMS Strategy) to reflect the changes made to the economics and environmental assessment as a result of the 'scheme challenge' and development work undertaken on the A14 junction with Brampton Road.

1.3 Structure of the Report

The Stage 2 Scheme Assessment Report Part II is structured into a further four chapters:

Chapter 2 describes the Alternative Proposal;
Chapter 3 presents a detailed engineering assessment of route options in terms of highway alignment, junction layouts, existing and new structures, geotechnics and contaminated land, earthworks, public utilities and compliance with Standards. Significant engineering difficulties associated with route options are also identified;
Chapter 4 presents a summary of the environmental assessment of scheme options, including Appraisal Summary Tables (ASTs);
Chapter 5 summarises the traffic analysis undertaken, and presents traffic forecasts and economic assessment of route options;

2. scheme proposals

2. Scheme Proposals

2.1 Description of the CHUMMS Strategy

The CHUMMS Strategy is identical to the Orange Route Option with Junction Strategy B as discussed in SAR Part I. Therefore reference should be made to SAR Part I Volume I Part A Section 3.1.4.

2.2 Description of the Alternative Proposal

2.2.1 A14 Mainline

As can be seen from Figure 2.1, the Alternative Proposal follows the same route as that of the CHUMMS Strategy, shown in Figure 3.5 of Part I Volume I Part A of the SAR. The proposal commences to the west of the existing Brampton Hut Junction with the A1. From here it travels adjacent to the west of the A1 and in doing so maintains one corridor of traffic in this area.

After crossing the A1 between Brampton and Buckden the Alternative Proposal passes to the south of Buckden Landfill Site before crossing the River Great Ouse and East Coast Mainline railway. It continues eastwards to the south of the Wood Green Animal Shelter and north of the villages of Hilton and Conington. It then passes to the south of Fenstanton and the closed Conington Landfill Site prior to tying into the existing A14 to the south of Fen Drayton.

From this point the Alternative Proposal is identical to the CHUMMS Strategy, comprising widening of the existing A14 and the Cambridge Northern Bypass (CNB) to Fen Ditton, with the exception of a short section at Bar Hill. At this location the route moves offline to the north of Bar Hill, between Lolworth Spring and the Girton Interchange by a distance of 110 metres at its maximum point to allow a new junction to be constructed to replace the existing one.

In locations, where the existing A14 is widened, provision will be made for local traffic in the form of a Local Access Road (LAR). In most areas the LAR runs adjacent to the proposed A14 and ties into the existing A14 when the route moves offline at Fen Drayton. The existing A14, west of Fen Drayton will be maintained as a strategic route carrying east-north traffic flows while the proposed offline section will carry east-west and east-south traffic flows.

2.2.2 Junction Strategy

As with the CHUMMS Strategy, the Alternative Proposal has nine associated junctions, as listed below:

Brampton Interchange
Fen Drayton Interchange
Trinity Foot Junction
Bar Hill Junction
Dry Drayton Junction
M11 Junction 14 Histon Junction
Milton Junction
Fen Ditton Junction

A description of these junctions is provided in Section 3.2.2 where they differ from those detailed in Part I of the SAR for the CHUMMS Strategy.

Figure 2.1 - Alternative Proposal Mainline

2.3 Cost Estimate

2.3.1 Basis of Estimate

As mentioned briefly in Section 1.2, since the various route options were reported on in SAR Part I, the capital costs of the CHUMMS Strategy was subjected to an internal 'scheme challenge'. This challenge involved a 'top down' comparison of the scheme cost estimate against available out-turn costs for similar completed schemes for which Atkins had access to detailed cost information. (This approach was adopted to provide a contrast to the 'bottom up' approach used to derive the cost estimates). The process also entailed a detailed review of the additions made to the cost estimates to represent:

preliminaries and traffic management;
preparation and supervision;
optimism bias;and
risk.

The challenge resulted in a reduction in the estimated cost of the CHUMMS Strategy. This means that the costs included in this report are lower than those attributed to the same scheme in Part I of the SAR (where the option is reported as the Orange Route Option with Junction Strategy B). The earlier, pre-challenge costs have been retained in Part I of the report to provide consistency between the costs of the Orange Route Option and those attributed to the other options (Blue and Purple Routes and options involving Junction Strategy A) which have not been subject to the same cost challenging exercise. Table 2.1 below summarises the costs estimated for the CHUMMS Strategy together with those estimated for the Alternative Proposal.

As explained in SAR Part I, the costs in Table 2.1 are estimated to third quarter 2001 (Q3/2001) to enable them to be readily compared to the Highway Agency's current Scheme Budget and previous estimates prepared for the HA.

Scheme Element	Option
Scheme Element	CHUMMS Strategy £m	Alternative Proposal £m
Preliminaries	36.756	33.318
Roadworks	81.315	71.493
Earthworks	34.148	33.835
Structures	88.738	79.774
Land	17.493	17.493
SU	15.181	15.181
Preparation & Supervision	38.06	36.969
Risk Allowance (non land costs)	55.769	55.769
VAT Allowance	37.282	33.418
Optimum Bias (5%)	19.362	17.988
Inflation Allowance	84.421	78.359
TOTAL	508.526	473.597

2.3.2 Comparison of Estimates

The Alternative Proposal has a reduced carriageway width to that of the CHUMMS Strategy between Brampton and Fen Drayton with corresponding cost savings in earthworks and pavement. The narrower deck widths of the River Great Ouse viaduct and the Brampton Interchange structures that result from this also produce cost savings. There is however, additional cost associated with the requirement to provide accommodation tracks adjacent to the existing A14 in the Alternative Proposal to minimise direct farm access onto the existing road. This is discussed in more detail in Section 3.2.1.

The requirement to replace the Huntingdon Viaduct by 2012 is not altered by the Alternative Proposal and therefore no costs for viaduct work have been included in the cost estimate for this scheme.

Reference should be made to Table 3.1 in Appendix A of Volume I Part B, which lists the above engineering parameters for both the CHUMMS Strategy and the Alternative Proposal.

3. engineering assessment

3. Engineering Assessment

3.1 Introduction

This chapter presents a detailed engineering assessment of the Alternative Proposal in terms of highway alignment, junction layouts, existing and new structures, geotechnics and contaminated land, earthworks, public utilities and compliance with Standards. Significant engineering difficulties associated with the proposal are also identified. Since the CHUMMS Strategy is identical to the Orange Route Option with Junction Strategy B, in terms of engineering, reference should be made to Section 4.4 in SAR Part I.

3.2 Alternative Proposal

3.2.1 Mainline Alignment

The alignment details of the Alternative Proposal are shown on drawing numbers 5021044/DR/HW/230 to 239 and 240 to 241. As shown on the drawings the proposed dual 2 lane all purpose (D2AP) A14 leaves the existing A14 corridor to the west of Brampton Hut Junction and heads south, adjacent to the west of the A1 before crossing it approximately mid-way between Brampton and Buckden.

The A14 continues eastwards as a D2AP carriageway, passing to the south of the Buckden South Landfill Site and crossing the River Great Ouse and its floodplain and the East Coast Mainline railway on a multi-span viaduct. It then travels to the south of the Wood Green Animal Shelter and in doing so crosses a number of local roads, which are listed below:

Offord Road
Silver Street
The A1198
Mere Way
The B1040
Hilton Road
Conington Road

The route then passes approximately 1.5km to the north of the village of Hilton before continuing eastwards to the south of Fenstanton and the Conington Landfill Site prior to rejoining the existing A14 at the site of the Fen Drayton Interchange. At this location the A14 gains a lane and continues as a Dual 3 Lane All Purpose Road east to Fen Ditton, identical to the CHUMMS Strategy. This is described in more detail in Section 3.2.2 below.

With the exception of a 9 metre deep cutting approximately 2km in length, the Alternative Proposal generally follows the local topography. Where localised floodplains are crossed the alignment has been lifted approximately 2 to 3 metres, depending on the flood levels provided by the Environment Agency.

Both the horizontal and vertical geometry of this section has been designed to a standard above that of the desirable minimum. There are however relaxations and Departures from Standard required in order to realign the local road network in those areas affected by the route. These are discussed in more detail in Section 3.2.2.

The alignment of the new section of the Alternative Proposal described above runs along the same route and has the same vertical profile as the CHUMMS Strategy. The main difference between the two options is centred on the utilisation of the existing A14 trunk road and the replacement of the Huntingdon Railway Viaduct. As discussed briefly in Section 1.2, the Alternative Proposal involves replacing the Huntingdon Viaduct, which has a residual life of less than 10 years, and maintaining the existing A14 carriageway as a D2AP carrying traffic from the north to the east, and vice versa. The new section of the A14 will carry traffic between the east and the west as well as to and from the south. By keeping the existing A14 operational as a strategic traffic route the new section of the A14 will carry approximately two-thirds of the traffic flows of the CHUMMS Strategy. Therefore, between the A1 and Fen Drayton the Alternative Proposal has been designed as a D2AP standard road.

In order to improve safety on the existing A14, a review of the direct farm accesses onto the A14 carriageway has been undertaken. Localised accommodation tracks adjacent to the existing road have been incorporated into the scheme between Huntingdon and Fen Drayton Interchange. These accommodation tracks link those properties that currently have direct access to the existing A14 and divert them to the nearest main junction where acceleration and deceleration lanes assist in providing a safer merge and diverge movement onto the A14.

As a result of the mainline horizontal and vertical geometry remaining unchanged from that of the CHUMMS Strategy, the realignment of local roads affected by the route remain the same. The significant difference, in terms of sideroads, between the options is at the proposed A1 Brampton and Fen Drayton Interchanges, which are discussed in Section 3.2.2 below.

3.2.2 Junctions

A1 BRAMPTON INTERCHANGE

The proposed interchange arrangement, shown on drawing number 5021044/DR/HW/278, involves a restricted movement option that links the existing A1 Southbound carriageway with the proposed A14 Eastbound carriageway, and the proposed A14 Westbound carriageway with the existing A1 Northbound and Southbound carriageways. The proposed A14 Westbound to A1 Northbound Link crosses over the existing A1 and passes under the proposed A14 before tying into the A1 Northbound carriageway at the existing Brampton-Grafham Road structure.

The vertical profile of the A14 Westbound to A1 Northbound Link requires sub-standard vertical geometry in order for it to pass under Brampton Road and over the A1 before passing beneath the proposed A14. This is discussed in more detail in Section 3.1.3.

The alignment of these links remains the same as for the CHUMMS Strategy, however the number of lanes on some of the links and the geometry of the merges and diverges on all links have been modified. This modification is a result of the reduction in traffic that will use this section of the A14 and Brampton Interchange since the existing A14 will be carrying approximately two-thirds of the traffic volume.

The A14 Westbound/A1 Northbound and A1 Southbound/A14 Eastbound links have been reduced in cross section from a two-lane to single-lane carriageway. The A14 Westbound/A1 Southbound Link remains as a single-lane carriageway. Simple taper merge and diverge layouts tie the links into the main carriageways of the A1 and A14. By modifying the merge and diverge on the A1 northbound and southbound carriageways respectively the A1 weaving issue generated by the CHUMMS Strategy is removed and there is no longer a requirement to widen the A1 between Brampton Interchange and the existing Brampton Hut Junction. The desirable minimum distance of 1km, as stated in the Design Manual for Roads and Bridges (DMRB) TD22/92 is achieved between the successive junction slip roads.

On joining the proposed A14, the A1 Southbound to A14 Eastbound Link ties into the A14 carriageway as a taper merge. The need for a lane gain merge on the eastbound carriageway, as well as a lane drop diverge on the westbound carriageway, as required for the CHUMMS Strategy is removed due to the reduction in traffic flows using the proposed road.

FEN DRAYTON INTERCHANGE

The general layout of the Fen Drayton Interchange (Refer to drawing number 5021044/DR/HW/279) involves a two-tier, restricted movement interchange linking the proposed A14 with the existing A14. The movements that can be made on the interchange are as follows:

Proposed A14 Eastbound to proposed LAR Eastbound
Existing A14 Eastbound to proposed A14 Eastbound
Proposed A14 Westbound to existing A14 Westbound
Proposed LAR Westbound to proposed A14 Westbound.

Westbound. All other movements, for example proposed A14 Eastbound to existing A14 Westbound, are made using the Trinity Foot Local Access Road Junction situated approximately 1 km east of the Fen Drayton Interchange.

Interchange. At the location of the Fen Drayton Interchange, the proposed A14 is on an embankment of between 2 and 3 metres so that the road sits above the maximum flood level of a floodplain in the area. This results in the vertical profile having to be designed so that it crosses over the A14, which in turn produces a design that requires large amounts of fill material to construct embankments up to 10 metres high in places.

The main difference between Fen Drayton Interchange in the CHUMMS Strategy and the Alternative Proposal is the link design and how they tie into the proposed A14. As this is where the two A14 routes bifurcate in the Alternative Proposal the combined traffic flows require that the proposed A14 to the east of the interchange be a D3AP standard road. Therefore, in order to make the transition between D2AP and D3AP standard road the eastbound merge and westbound diverge take the form of a lane drop and lane gain respectively, in accordance with TD 22/92 of the DMRB. In comparison, the CHUMMS Strategy sees the lane gain and lane drop occurring at the A1 Brampton Interchange and therefore D3AP is maintained through Fen Drayton Interchange with simple taper merges and diverges connecting the links to the mainline.

All interchange links have been designed without the need for Departures from Standard although some relaxations have been required in order to minimise structure spans and reduce land take. Where these relaxations have been applied to the geometry of the links, verge widening and parapet and abutment setbacks have been applied to ensure that stopping sight distances are achieved.

GODMANCHESTER EMERGENCY ACCESS JUNCTION

Although not shown in detail on the drawings, consideration has been made to the provision of a junction where the A1198 crosses over the proposed mainline south of Godmanchester. This junction would be for the use of emergency vehicles in account of the fact that access onto the proposed D2AP A14 is limited to the A1 Brampton and Fen Drayton interchanges over a distance of approximately 13km. It would also allow queued traffic to leave the A14 in the event of an accident.

It is considered necessary that this additional junction be included in the Alternative Proposal due to the risk of the 2 lane carriageway of the D2AP standard road becoming impassable due to a road traffic accident or incident. A junction midway between the two interchanges will allow emergency access to and from the main carriageway without the need for excessive distances to be travelled.

The junction itself would comprise four gated slip roads linking the realigned A1198 with the D2AP carriageway of the proposed A14. Only a simple T-junction would be required to connect the slip roads to the A1198, as movement to and from these slips would be by emergency vehicle only.

3.2.3 Structures

EXISTING STRUCTURES

Existing structures along the scheme have been discussed in Section 2.5 of SAR Part I. Table 3.2 of Appendix B lists those structures affected by the Alternative Proposal and makes recommendations as to their treatment under this project.

NEW STRUCTURES

The number of new structures on the Alternative Proposal is the same as the CHUMMS Strategy (refer to Appendix C in SAR Part I, Volume I, Part B). However, for the Alternative, the narrower A14 Westbound/A1 Northbound Link results in a reduction in deck width of 3.0m for Underbridge No. 6.04 and a reduction in span of 3.0m for Underbridge No. 5.03 (Refer to drawing number 5021044/DR/HW/278 in Volume II Part A).

A small cost saving could be achieved by reducing the overbridge spans quoted in the SAR Part I to allow for the reduced carriageway widths associated with the Alternative Proposal. However, any future widening would then require the bridges to be demolished and rebuilt, the cost of which would be much greater than any initial saving. The overbridge spans assumed for the Alternative Proposal are therefore the same as those quoted for the CHUMMS strategy.

RIVER GREAT OUSE VIADUCT

VIADUCT A possible arrangement of the viaduct is shown on drawing number 5021044/DR/BR/026 in Volume II, Part B.

The width of the central reservation over the structure is shown as 2.5m including hard strips, as permitted by clause 4.8 of TD27/96 for long underbridges. At the west end, the structure will have to be widened over a length of approximately 100m to allow for sight line requirements.

HUNTINGDON RAILWAY VIADUCT

Brief details of the existing viaduct and retaining walls are given in Table 3.2 in Appendix B.

The deck, and possibly the piers, of the viaduct will need to be replaced. This can be undertaken once the new A14 to the south of Huntingdon has been opened, allowing the existing A14 through Huntingdon to be closed whilst the viaduct is demolished and rebuilt.

3.2.4 Relaxations and Departures From Standards

Standards As a result of various constraints along the scheme corridor it has been necessary when designing the scheme to drop below desirable minimum standards in certain locations, as permitted by the Highway Agency's Design Manual for Roads and Bridges (DMRB).

As discussed in Section 3.2.1 the vertical profile of the A14 Westbound to A1 Northbound Link has a number of constraints that were required to be taken account of in the design. The combination of these constraints results in a vertical crest curve that is one step below desirable minimum. A one step relaxation of a crest curve automatically produces a one step relaxation in the vertical stopping sight distance, as the radius of the curve becomes too tight to be able to achieve the desirable sight envelope. In accordance with the DMRB the relaxation in the vertical element together with the relaxation in the vertical stopping sight distance requires a Departure from Standard, which has been approved by the Highways Agency. Drawing numbers 5021044/DR/HW/614 and 615 provide more details on this.

The Alternative Proposal mainline has been designed within standards without the need for any relaxations or Departures from Standard. Relaxations were however required in the design of Fen Drayton Interchange as well as in the realignment of some of the existing roads in order that they could be taken across the proposed A14 with minimal land take. One Departure from Standard was required on Conington Road side road resulting from a substandard curve in close proximity to a junction.

Details of these relaxations and Departures from Standard are given on drawing numbers 5021044/DR/HW/610 and 611.

3.2.5 Earthworks

The earthworks between Ellington and the A1 are very similar for both the CHUMMS Strategy and the Alternative Proposal. The difference occurs at Brampton Interchange where the cross-sections of two of the links have been reduced for the Alternative option and along the A1 where widening is no longer required.

From the A1 Brampton Interchange to the A1198 the main earthworks required are the approach embankments to the River Great Ouse Crossing, which are up to 13 metres high in places and the cutting through the ridge to the south of Godmanchester, approximately 7 to 8 metres deep. There is also a pronounced cutting between Offord Road and Silver Street which is approximately 2 km in length and up to 11 metres deep.

From the A1198 to the point where the route ties into the existing A14 at Fen Drayton, the proposed vertical profile generally follows the surrounding topography, requiring only minor cuttings and low embankments. These low embankments have been designed into the scheme to ensure that the route runs above the flood levels of the floodplains that are located along the A14 corridor. Fen Drayton Interchange is situated on a floodplain and therefore requires embankments of up to 10 metres in order to lift the link roads over the A14.

For both strategies the junctions and side roads form the majority of the fill requirement. This is because all the side roads cross above the A14. For the more major side roads, the adoption of desirable crest curves, required in order to avoid Departures from Standard, have meant long lengths of high embankment.

Drawing numbers 5021044/DR/HW/235 to 239 provides details of the earthworks required along the scheme and Table 2.1 in Appendix A of Volume I, Part B provides an indication of the cut/fill ratio for the two strategies within this section of the scheme.

3.2.6 Contaminated Land

Contaminated land issues along the Alternative Proposal are common to those of the CHUMMS Strategy. Therefore reference should be made to Section 4.4 of SAR Part I

3.2.7 Public Utilities

The Public Utilities' (SU) apparatus that is affected by the Alternative Proposal is very similar to that of the CHUMMS Strategy. The main difference between the two strategies is on the A1 where BT cabling is located in the existing southbound verge. Approximately 500m of this is affected by the A1 widening as part of the CHUMMS Strategy but avoided in the Alternative Proposal since widening of the A1 is not required.

4. environmental assessment

4. Environmental Assessment

4.1 Introduction

The following sections cover the baseline conditions, mitigation and the assessment of environmental effects for each of the environmental topics. Refer to Volume 3 for copies of the Environmental Constraints Maps.

4.1.1 Background to the Environmental Addendum to the SAR

The objective of this part of the addendum is to appraise and compare, from an environmental perspective, the Alternative Proposal against the CHUMMS Strategy.

This addendum addresses topics previously assessed in the SAR Part I for the earlier route options. Generally the addendum describes the section from Ellington to Fen Drayton, the section between Fen Drayton Interchange and Fen Ditton being identical to that of the CHUMMS Strategy.

However due to the nature of methodologies for Noise and Air Quality assessments, chapters for these topics describe the impacts for the full length of the scheme, Ellington to Fen Ditton.

4.1.2 Traffic Considerations for Environmental Assessment

It is noted that the introduction of a junction at Brampton Road in the CHUMMS Strategy is likely to have implications on local traffic conditions across Huntingdon town centre as traffic patterns change due to the new access arrangements. Whilst an increase in traffic flows along Brampton Road could be expected, the traffic model is strategic in nature and hence not designed to examine the local impacts within Huntingdon. Therefore any changes in flow forecast at this stage should be treated with caution.

A more detailed study of the local effects of the Brampton Road junction needs to be undertaken, including traffic and environmental considerations, which also takes account of other potential local transport interventions and policy measures to complement the introduction of the scheme.

4. environmental assessment (continued)

4. Environmental Assessment (continued)

4.2 Traffic Noise and Vibration

4.2.1 Introduction and Method of Assessment

NOISE

Noise annoyance is defined by the World Health Organisation as 'a feeling of displeasure evoked by noise' and mainly effects people when they are in their homes or when they are in the streets. Individuals vary considerably in their sensitivity to traffic noise therefore the relationship between noise exposure and nuisance adopts the concept of an average or community annoyance rating for each noise level. The rating differs between a sudden and gradual (steady state) increase in noise. The sudden increase giving rise to a greater percentage of people annoyed compared with the same noise increase for steady state conditions.

A Stage 2 traffic noise and vibration assessment has been undertaken for the alternative options for a new route and widening works for the A14 between Ellington and Fen Ditton. Preliminary predictions of noise levels have been made for the options considered in the opening year (2010) Do Minimum, and a future year (2025) for the Do Minimum and Do Something scenarios. The effects of known development schemes (including that proposed at Northstowe) have been taken into account.

DESCRIPTIONS FOR THE MAGNITUDE OF EFFECT

The response of the human hearing system is logarithmic rather than linear in behaviour, and able to detect a noise level difference of about 1 dB(A) between two steady sounds, when presented in rapid succession under controlled laboratory conditions. The smallest change in environmental noise that is generally noticed by an individual over a period of time is about 3 dB(A). A 10 dB(A) change approximates to a subjective doubling or halving of loudness.

STUDY AREA

The study area has been split into two levels of detail:

A fully-modelled area close to the existing A14 and CHUMMS road corridors;
An indicative area covering roads where there may be significant changes in traffic flow.

TRAFFIC DATA

Existing 2003 traffic flows for the section of the A14 covered by this study are in range between 15,000 to 25,000 (18-hr AAWT) west of the A1 near Brampton, up to 80,000 between the A1 and M11 and over 100,000 east of the M11 junction. It is known that traffic congestion can occur frequently causing a speed reduction which has been taken into account. It can be shown that there is approximately 1dB reduction for each 10km/h speed reduction from 108 to 48km/h.

This noise assessment has been carried out for the CHUMMS Strategy and the Alternative Option only and the forecast traffic flows and speeds have been taken into account.

METHOD OF ASSESSMENT

At this stage there has not been any consultation with local authorities regarding issues on noise.

CRTN is the methodology used to determine entitlement under the Noise Insulation Regulations 1975 (as amended 1988) and is the accepted method for the prediction of traffic noise in the UK.

To provide information on the existing noise levels in rural areas where it was not reasonably possible to carry out noise calculations, a preliminary noise survey was undertaken in October 2003 by Atkins. These measurements concentrated on areas where existing levels are low or where local roads may have some effects.

The incremental effect of each option was calculated as outlined in TAG in order to estimate the number of people that are likely to be bothered by increased noise.

Noise contours were generated along the proposed composite alignments using CTRN;
Areas exposed to 55dB or more have been identified.

LIMITATIONS

CRTN has been developed from extensive measurement data and validated out to distances up to 300 metres from trafficked roads. However some extrapolation is acceptable for planning purposes.

In the case of this study, extrapolated levels well beyond 300 metres from roads have been made in order to make the necessary determinations of the extent of noise impacts. It has generally been necessary to limit the extent of the study within areas where noise levels are 55dB or more. Such levels may be found as much as 1km from the A14. From limited measurements, some quiet rural areas exist where levels may be lower although, there is insufficient data to form a reliable objective comparison. However, indications of such quiet areas have been outlined under 'Baseline Conditions'. In order to make quantitative determinations with reasonable accuracy, it would be necessary to have further data at locations where noise levels are low. It would also be necessary to have more precise and certain data on road alignments and earth works to determine overall impact with greater accuracy.

In areas of open land that are enjoyed as a general public amenity, the effect of noise can be important. Guidance on noise is provided by the World Health Organisation (WHO). They have indicated that "daytime outdoor noise levels of less than 55 dB LAeq (approximately equal to 58dB LA10, (18 hour)) are desirable to prevent any significant community annoyance" and this has been restated in PPG 24 Planning and Noise - Noise exposure Categories: Explanation of Noise levels, paragraph 4, and page 11.

4.2.2 Baseline Conditions

GENERAL

The findings of the noise survey and calculated data has been used as the basis for comparison. These take into account the present effects of road surface conditions, a thin wearing course surface reduces noise by up to 3dB compared to a normal hot-rolled asphalt surface. Where speeds are less than 75km/h noise levels are 1dB lower.

All noise levels are in terms of LA10 (18 hour).

AREAS ADJACENT TO THE EXISTING ROUTE

A14 between Ellington and A1 near Brampton

The area is open countryside with isolated dwellings situated at some distance from these roads. However, noise levels from these are evident in most parts of the area with levels measured above 50dB except at Brampton Wood. Calculations confirm that most of the area of this woodland is below 50dB.

Levels of 60dB or more affect all areas within approximately 250m to 300m of the A14 and A1M but near the junction the combination of the two sources extends noise over a wider area than each road on its own. Levels of 55dB or more may extend as far as 600m from the A14 and 500m of the A1 but more near the junction.

A1 South of the A14 Interchange

Interchange The A1 between the A14 and Buckden Road Interchanges, affects the housing areas on western side of Brampton with levels in the low 60s dB at the nearest houses that are within 250m and 55dB or more up to 500m and in some places, greater distance near the junction.

A14 between A1 near Brampton and A141 near Stukeley Junctions

The present A14 affects the houses on the north side of Brampton with most above 55dB at up to 500m distance. At Hinchingbrooke Country Park, which is partly on ground rising from the road, noise levels of 55dB or more are found within 700m each side of the A14 with additional noise from the B1514 thus affecting most of the park and the racecourse.

A14 between A141 near Stukeley and A1198 Junctions

On the northern side of the A14, which has a noise reduced surface, there are the extensive housing areas of Stukeley and the southern side of Huntingdon. Taking into account the present environmental barriers and bunds, noise levels are 60dB or more within 200 to 250m of the A14 and 55dB or more within approximately 700m.

Parts of Hinchingbrooke Hospital are exposed to levels above 55dB. Within the areas to the east of the B1514, those to the north of the B1044 and west of the A1198, there are further areas of housing close to the A14. Taking into account the present environmental barriers, noise levels are 60dB or more within 350m of the A14 and 55dB or more within 800m and further where there are additional contributions of noise from other roads.

A1198 to A1096/B1040 Galley Hill Junctions

The houses on both sides with housing developments on the southern side of Hemingford Abbotts and Hemingford Grey experience 60dB or more within approximately 250m of the A14, which has a noise reduced surface and 55dB or more within approximately 500m. The more distant effects of traffic noise with levels of 50dB or more affects the southern side of Hemingford Grey.

A1096/B1040 Galley Hill to west of B1050 Bar Hill Junctions

Noise levels are 60dB or more within 250 to 300m of the A14 and 55dB or more within 500 to 600m but less within the housing at Fenstanton on account of the existing environmental barriers.

Fen Drayton is affected by distant A14 noise with levels of approximately 50dB on the southern fringes.

B1050 Bar Hill to M11 Interchange at Girton

Noise levels are 60dB or more within 300m of the A14 which has a noise reduced surface and 55dB or more within 500 to 600m but less within the housing area of Bar Hill.

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

A14 from Girton to B1047 Fen Ditton

Noise levels are 60dB or more within 300m of the A14 and 55dB or more within 600m. However at Girton, where the road is in cutting, houses up to 180m are affected by levels of 60dB or more with those closest in the 65 to 70dB range. Similar levels affect the nearest houses around Histon Junction.

AREAS ADJACENT TO CHUMMS STRATEGY

The following applies to both the CHUMMS Strategy and the Alternative Proposal.

A14 between Ellington and A1 south of Brampton

Noise levels south of the landfill site and Station Farm are isolated houses likely to be in the low 50's dB or lower in parts.

A1 to Great Ouse Bridge near Offord

Open areas to the south of Offord Cluny to the south are likely to be in the 40's dB with little effects from major roads.

Offord to A1198 south of Wood Green Animal Shelter

Open areas and isolated buildings that exist with noise levels are in the upper 40's and low 50's. Close to local roads, such as the A1198, levels can be much higher.

South of Wood Green Animal Shelter to Fenstanton

Open areas to the north of Hilton where levels are in upper 40's and low 50's dB.

Fenstanton to Bar Hill

The open countryside to the south of Fenstanton and to the north of Conington have some noise influences of the existing A14 with levels of 55dB or more within 550m of it and 60dB within 250m.

CHANGES BETWEEN PRESENT AND OPENING YEAR (2010)

Changes between the present and 2010 will be related to traffic growth and any effects of resurfacing the existing roads with quieter surfaces. For the purposes of the following, the 2010 situation is taken as the basis for comparison.

4.2.3 Key Issues/Areas

Both the options would introduce noise into rural areas that are presently little affected by noise. However, the impact of noise will be dependent upon how quiet the present area is. This is dependent on:

The distance from the existing A14 and A1 (M).
Effects of traffic on local roads.
Benefits of providing environmental barriers

This is an area which is largely low-lying or generally undulating. There are few road cuttings and most of the existing A14 is near or slightly above the surrounding ground level. As a result, noise from this road tends to propagate over wide areas as described previously.

There would be limited opportunities to place any of the options within significant cuttings or provide substantial earth bunding so as to provide a significant reduction in the lateral spread of noise. Consequently, any option considered should be sited as far as possible from where people live. However, this would have the effect of introducing noise into areas of countryside that are presently subject to low levels.

4.2.4 Mitigation Measures

On the basis of current Highways Agency advice, resurfacing with a thin wearing course (TWC) would reduce noise levels by 2.5dB(A).

Acoustic fences and/or earth bunds could reduce noise levels by up to 15dB(A) if they are of a sufficient size. However, where screening is only partial, noise reductions of 5dB(A) or less would be expected and beyond 300m are unlikely to have much effect, particularly where the road is at grade and the surrounding area is level.

Noise mitigation will be required in a number of areas for both options as outlined and it is assumed that all environmental noise barriers would be reflective. Mitigation has not been considered for the exiting A14 except where improvements are proposed.

4.2.5 Assessment of the two Options

This Scheme Assessment Report provides details of the effects of the CHUMMS Strategy and Alternative Option only.

The options are compared with the 'Do Minimum' scenario using the TAG criteria and, where appropriate, taking into account the outlined mitigation measures described previously. Indicative noise contour maps have been prepared showing the free-field noise levels in 5dB bands from 55 to 75dB at 5m above existing ground levels within a limited distance from the road (generally no more than 500m from the road where there are noise sensitive areas). In addition, a noise contour map has also been prepared for the 'do minimum' scenario. All situations relate to 2025.

All options include the effects of noise from the section that comprises the Cambridge Northern Bypass. In the case of the 'do minimum' scenario, this considers the present road layout and necessary changes that would need to be made by 2025. For the 'do something' options environmental barriers would be acoustically absorptive except where it has been shown that conventional reflective barriers would cause no adverse impact to people.

DO MINIMUM

By the assessment year (2025) traffic increases would, in general cause noise levels to be 1 to 2dB higher than those in the do minimum (2010). However, where traffic congestion increases, such noise increases may not occur.

It is expected that all of the A14 would be resurfaced in a quieter material by the year 2025. In addition, a new single carriageway road link would be built between Bar Hill and Dry Drayton. A new Huntingdon Viaduct would be built on the line of the present one.

Table 4.1 - Summary of the Effects of Do Minimum 2025
Number of Properties Affected by Noise Levels	Do-Minimum
Number of Properties Affected by Noise Levels	2010	2025
55 to <60dB	31,380	31,288
60 to <70dB	1,862	1,934
70dB or more	210	231
Number of properties affected by changes in noise levels: Do Minimum 2010 v Do Minimum 2025	Changes
Increase 1 to <3dB	1,384
Increase 3dB or more	0
Decrease 1dB or more	0

The number of properties that would be within 300m of the centreline of the A14 is 555 at between 0-100m, 1,232 at between 100-200m and 1,712 at between 200-300m.

ROUTE OPTIONS

The CHUMMS Strategy and Alternative Proposal have been examined. To illustrate the general impact of these and the 'Do Minimum' situation, indicative 1:50,000 scale noise contour maps have been prepared. These are included in the EAR.

The following table summarises the effects of noise within the study area and where houses are affected by noise levels of 55dB or more.

Table 4.2 - Summary of Options
Number of Properties Affected by Noise Levels
Noise	CHUMMS	Alternative
55 to <60dB	32,195	31,586
60 to <70dB	1,115	1,677
70dB or more	142	190
Number of properties affected by changes in noise levels: Do Minimum 2010 v Option 2025
Increase 1 to <3dB	910	1,327
Increase 3 to <5dB	84	89
Increase 5 to <10dB	18	3
Increase 10 to <15dB	0	1
Increase 15dB or more	1	1
Decrease 1 to <3dB	2,506	1,946
Decrease 3 to <5dB	629	86
Decrease 5 to <10dB	886	63
Decrease 10 to <15dB	24	12
Decrease 15dB or more	6	6

ASSESSMENT

The number of properties that would be within 300m of the centreline of new roads is 215 at 0-100m, 432 at 100-200m and 939 at 200-300m. This applies to both the CHUMMS Strategy and Alternative Proposal.

On the basis of TAG and compared with the 'Do Minimum' situation 2024 there would be a net decrease of 407 people that would be annoyed by noise with the CHUMMS Strategy. With the Alternative Proposal there would be a net decrease of 149. On balance, the CHUMMS Strategy is the most favourable. However, this assessment does not include people who are affected by changes in noise where levels do not reach 55dB.

OTHER AREAS AFFECTED BY NOISE CHANGES FROM TRAFFIC RE-DISTRIBUTION

Some areas outside the route corridors above are expected to be affected by changes in traffic. The extent of these traffic changes and the consequential effects on traffic noise are dependent on the layout and location of the junctions required to gain access to the A14 route. The following table outlines the effect arising from the two options considered.

Table 4.3 - Estimated Number of Houses outside the Noise Model Affected by Changes in Noise from the CHUMMS Strategy and Alternative Proposal
Change in Noise Level	CHUMMS Strategy	Alternative Proposal
3 to <5dB increase	2,515	0
0	0	0
0	0	0
0	0	0
3 to <5dB decrease	108	57
5 to <10dB decrease	5	0
10 to <15dB decrease	114	0
15dB or greater decrease	0	0

CHUMMS Strategy

The extent of expected changes in noise of 3dB or more in the case of CHUMMS Strategy are extensive as outlined in the following table.

Table 4.4 - Extent of Noise Changes outside the A14 Corridors
Road	Section	Change in noise dB	No. Houses
Hilton Road	between Conington Road and High St/Church End	-14	47
Church End	between Hilton Road and Potton Road	-13	67
Cambridge Road	A14 to Fen Drayton	-8	5
Boxworth Road	between Brockley Road and Elsworth Road/High St Knapwell	-3	108
St Johns St	between B1514 and B1044	3	953
B1514	Huntingdon between junction with B1044 and B1514 ring road	3	433
B1044	between St Peters Road and B1514, Huntingdon	4	864
Great North Road	between A1(M) and Alconbury, West of A1(M)	4	110

Alternative Proposal

By 2025, the effects of noise changes outside the A14 corridors with the Alternative Proposal would be much less extensive than and there would be only be 3 to 5dB decreases to houses near Park Lane, School Hill and High Street between Bell Hill and Station Road.

The Alternative Proposal would require the rebuilding of the viaduct after the new route is operational. This would mean that the effects of noise outside the A14 route corridors for interim situation would essentially be as for the CHUMMS Strategy.

4.2.6 Summary and Conclusions

EXISTING SITUATION AND DO MINIMUM

At present there are a large number of people affected by noise arising from the A14 between Ellington and Fen Ditton. There are almost 3,500 houses within 300m of the present route between these places and by 2010, over 1,850 are affected by noise levels from the A14 of 60dB or more if no scheme is built and almost 1,950 by 2025.

OPTIONS AND ASSUMPTIONS

Two options have been assessed, the CHUMMS Strategy and an alternative that retains the existing A14 as a through route, the Alternative Proposal.

For both options, the same simple 2m or 3m high environmental noise barriers or earthworks have been considered for mitigating noise from the new roads. Both options assume quiet road surfaces.

The effects of noise changes in areas situated some distance from the A14 where levels are below 55dB has not been carried out at this stage. In order to make such determinations with reasonable accuracy, it would be necessary to have further data at locations where noise levels are low. It would also be necessary to have more precise and certain data on road alignments and earth works.

GENERAL EFFECTS OF THE OPTIONS

The CHUMMS Strategy would remove much of the impact of noise at Godmanchester. However, risks of noise increases remain at the quiet areas of Buckden and Offord Cluny with further risks at Hilton, an area where present levels are low.

East of Trinity Foot the scheme is on-line and there are opportunities to mitigate noise at most locations that are within 200 or 300m of the route. Some barriers would provide significant reductions on present levels at those houses most affected. However, beyond that distance and where other roads have influence, noise levels may be increased due to the increased traffic, reduced congestion and limited extent that barriers could reduce noise.

Table 4.5 - Summary of Changes in Noise and Nuisance: All Options
Option	Number of People Annoyed	Net Change from Do Minimum	Number of Houses affected by Noise Increases 1dB or more 2010 Do Minimum v 2024 with Scheme
Do Minimum	7,221		692
Options
CHUMMS Strategy	6,814	-407	1,013
Alternative Proposal	7,072	-149	1,421

NOISE CHANGES FROM TRAFFIC OUTSIDE THE PRESENT A14 AND THE OPTIONS

Outside the A14 route corridors, the construction of the CHUMMS Strategy would affect increases of 3dB or more at over 2,300 houses with decreases of 3dB or more at less than 230. The Alternative Proposal would have much less effect with just 57 houses benefiting from a 3dB or more decrease.

4.2.7 Conclusions

The CHUMMS Strategy would mean that there would be a net reduction of 407 people annoyed by noise compared to 149 with the Alternative Proposal.

In the areas of the A14 corridors, over 1,000 houses would be affected by a noise increase of 1dB or more with the CHUMMS Strategy compared to over 1,400 with the Alternative Proposal. The CHUMMS Strategy would effect noise decreases of 1dB or more at over 4,000 houses (equivalent to approximately 9,600 people) compared to just over 2,100 (5,040 people) with the Alternative Proposal.

Away from the A14 Corridor, the CHUMMS Strategy would affect increases of 3dB or more at over 2,300 houses (approximately 5,500 people) with decreases of 3dB or more at less than 230. These are concentrated on Brampton Road and the western quadrant of Huntingdon inner ring road, reflecting the changed access arrangements into Huntingdon with local traffic diverted off existing routes, and the A1 corridor. Reference should be made to paragraph 1.11 on traffic considerations.

The Alternative Proposal would have much less effect with just 57 houses (approximately 137 people) benefiting from a 3dB or more decrease and no properties would experience an increase of 3dB or more.

4. environmental assessment (continued)

4. Environmental Assessment (continued)

4.3 Air Quality and Greenhouse Gases

4.3.1 Introduction

This section details the Stage 2 air quality assessment for the Alternative Proposal for the proposed A14 improvements between Ellington and Fen Ditton, Cambridgeshire.

Vehicle exhausts contain a number of pollutants including carbon dioxide (CO2), carbon monoxide (CO), hydrocarbons, oxides of nitrogen (NOx) and particles. The quantity of each pollutant emitted depends upon the type and quantity of fuel used, engine size, speed of the vehicle and abatement equipment fitted. Once emitted, the pollutants disperse in the air. Pollutant concentrations in the air can be measured or modelled and then compared with ambient air quality criteria.

4.3.2 Air Quality Criteria and Pollutants

Air quality criteria can be readily divided into two groups; those that are mandatory and those that are designed for guidance. Mandatory criteria that apply to the UK are the objectives from the Air Quality Strategy (AQS) for the UK and the European Community Directive limit values, which are incorporated into Regulations. The air quality criteria used in this assessment are given in the following table.

Table 4.6 - Air Quality Criteria
Pollutant	Criteria	Date to be Achieved by	Objective
NO2	Annual Mean	2005	40
NO2	Hourly mean	2005	18 exceedances
PM10	Annual Mean	2004	40
PM10	24-Hour Mean	2004	35 exceedances
PM10	Annual Mean (provisional)	2010	20
PM10	24-Hour Mean (provisional)	2010	7 exceedances
CO	Maximum daily 8-hour running mean	2003	10
Benzene	Running Annual Mean	2003	16.25
Benzene	Running Annual Mean	2010	5
1,3 butadiene	Running Annual Mean	2001	2.25

It should be noted that whilst the current annual mean AQS objective for PM10 is 40µg/m³, with 35 exceedances of the 24-hour mean AQS objective, a more stringent objective of 20µg/m³, with 7 exceedances of the 24-hour mean is to be applied in 2010, although currently these objectives are provisional and not included in Regulations.

AIR POLLUTANTS

POLLUTANTS Nitrogen Dioxide (NO2)

Nitrogen dioxide is a secondary pollutant produced by the oxidation of nitric oxide (NO). Nitric oxide and nitrogen dioxide are collectively termed nitrogen oxides (NOx). Approximately half of the UK NOx emissions are from road transport. The majority of NOx emitted from vehicles is in the form of nitric oxide, which oxidises rapidly in the presence of ozone to form nitrogen dioxide. In high concentrations, nitrogen dioxide can affect the respiratory system.

Particulate Matter

Particulate matter in vehicle exhaust gases consists of carbon nuclei onto which a wide range of compounds are absorbed. These particles are less than 10 µm in diameter. Particles with a median diameter of less than 10 µm are referred to as PM10. Diesel engines produce the majority of particulate emissions from the vehicle fleet. About a quarter of primary PM10 emissions in the UK are derived from road transport. Particulate matter appears to be associated with a range of symptoms of ill health including effects on the respiratory and cardiovascular systems, on asthma and on mortality.

Carbon Monoxide (CO)

The majority of carbon monoxide emitted in the UK is from motor vehicles. It is readily absorbed through the lungs and reduces the oxygen carrying capability of the blood.

Hydrocarbons

The term 'hydrocarbons' is used to include all organic compounds emitted from vehicles both in the exhaust and by evaporation from the fuel system, and covers many hundreds of different compounds. About one third of the UK hydrocarbon emissions are produced by road transport. Hydrocarbons are important precursors of photochemical smog and oxidising compounds. The DMRB requires an assessment for benzene and 1, 3-butadiene as these are included in the Air Quality Strategy. They are both genotoxic carcinogens and exposure to them is associated with certain types of leukaemia.

Carbon Dioxide

Carbon dioxide is a major product of the combustion of carbon containing materials. Carbon dioxide does not affect human health at ambient levels and so is not significant as a local pollutant but is important for its national and international role in climate change. About 20% of the UK carbon dioxide emissions are produced by road transport.

4.3.3 Existing Conditions

LOCAL AIR QUALITY REVIEW AND ASSESSMENT

All local authorities are required by Part IV of the Environment Act 1995 to review air quality in their area and to assess present and likely future air quality against set objectives.

If an area is identified as being unlikely to achieve the Air Quality Strategy (AQS) objectives, the local authority is required to designate an Air Quality Management Area (AQMA) and develop an action plan to improve air quality.

The following local authorities contain roads with a significant change in traffic (±10%) with the proposed improvements and/or a section of the existing or new alignment of the A14:

Cambridge City Council
Huntingdonshire District Council
South Cambridge District Council

Air quality review and assessment is a rolling process which requires periodic updating due to the changing nature of the air quality with time. A partnership of five local authorities in and around Cambridgeshire, including those listed above, was set up to carry out the review and assessment of air quality in Cambridgeshire. Following the completion of the first round of the review and assessment process none of the local authorities above have declared any AQMAs.

As part of the second round of the review and assessment process local authorities must complete an updating and screening assessment (USA) to identify matters that have changed since the first round of review and assessment and identify sources that may lead to an air quality objective being exceeded. A detailed assessment is required where there is a possibility of AQS objectives being exceeded.

Monitoring

Measurements of pollutant concentrations may be made by deploying analytical instruments that measure continuously and record the average concentrations over specified time intervals. Simpler sampling devices, such as diffusion tubes, adsorb pollutants over a longer time period and are subsequently analysed at a laboratory to give an average concentration for the sampling period. National survey results from both types of monitoring are published in the UK National Air Quality Information Archive¹, and the closest relevant data are summarised below.

Continuous Monitoring

Defra operates a network of automated continuous monitoring sites throughout the UK. The closest sites in the network to the study area are Cambridge Roadside, Norwich Centre and Wicken Fen. Descriptions of these sites are given below, together with their location in relation to the study area.

Cambridge Roadside is a roadside site in the centre of Cambridge, located approximately 4 km south of the A14. The monitor is located at first floor level at a height of approximately 4 metres and a distance of 2.5 metres from the kerbside of a busy urban road leading traffic directly to the city centre shopping area. Nitrogen oxides have been monitored since 1999. This site is located at grid reference 545300 258300.
Norwich Centre is an urban centre site located approximately 90km north east of the A14. The nearest road to the site is located approximately 12 metres away, although traffic flow is free flowing and very light (1 or 2 vehicles per minute observed off peak). O3, PM10, NOx and SO2 have been monitored since 1997 and benzene since 2002. This site is located at grid reference 623000 308900. Although located at some distance from the A14 this site was selected as it is the closest Defra site where PM10 and CO are monitored.
Wicken Fen is a rural site located approximately 12km north east of the A14. The area surrounding the monitoring station is open field with isolated trees. O3, NO2 and SO2 have been monitored between 1997 and 2002. This site is located at grid reference 556400 269200

Continuous monitoring is also undertaken by local authorities at locations given in the following table.

Site	Local Authority	Grid Reference	Site Type	Pollutants	Proximity to A14	Available Results
Parker Street	Cambridge City Council	545366 258391	Roadside	NO2, PM10	4km South of Girton Junction	2000-2004
Silver Street	Cambridge City Council	544758 258118	Roadside	NO2, PM10	4km South of Girton Junction	2000-2004
Gonville Place	Cambridge City Council	545508 257828	Roadside	NO2, PM10	4km South of Girton Junction	2000-2004
Regent Street	Cambridge City Council	545287 258124	Roadside	NO2, CO	4km South of Girton Junction	2000-2004
Newmarket Road	Cambridge City Council	546312 258896	Roadside	NO2, PM10	4km South of Girton Junction	2002
Huntingdon Ring Road	Huntingdon-shire DC	524056 271533	Roadside	NO2, PM10	120m North of A14 at Huntingdon	2000-2004
Godmanchester	Huntingdon-shire DC	524419 271312	Roadside	NO2, PM10	25m North of A14 at Godmanchester	2002-2004
Bar Hill	South Cambridge-shire DC	538650 263750	Roadside	NO2, PM10	On eastbound A14 Carriageway at Bar Hill	2001-2003
Impington	South Cambridge-shire DC	543850 261750	Roadside	NO2, PM10	On westbound Carriageway of A14 at Impington	2002-2003

Non-continuous Monitoring

Nitrogen dioxide can also be monitored passively using diffusion tubes. Local authorities across the UK take part in Defra's nitrogen dioxide survey and also carry out their own monitoring surveys.

Data from the following Defra sites are considered here:

Cambridge - 5 sites located approximately 3-4 km south of the A14 at Histon Junction;
Histon - 5 sites located approximately 2 km north of the A14 at Histon Junction;
Sawston - 2 sites located approximately 3 km east of the M11 between junctions 10 and 11/ 12km south of the A14 at Fen Ditton;
St Neots - 5 sites located approximately 12 km south southeast of the A14 at Huntingdon.

Local authorities monitor NO2 with diffusion tubes at the following number of locations:

Cambridge City Council - 42 locations;
Huntingdonshire District Council - 22 locations;
South Cambridgeshire District Council - 19 locations.

Full results from the monitoring locations described above are presented in the Environmental Assessment Report Addendum, but summarised below.

Monitoring Survey near A14

Atkins commenced in a year long nitrogen dioxide monitoring programme using diffusion tubes in June 2004. Nineteen sites were selected, based on the expected changes in traffic flows on the road network in the study area. The Environmental Assessment Report and Addendum give details of the location of sites.

As recommended by Defra's Technical Guidance³ three diffusion tubes were co-located with a continuous monitor (Cambridge Roadside site) to enable the accuracy and precision of the tubes to be determined. Comparison of the mean concentrations in each monitoring period gives a correction factor which can then be applied to the diffusion tubes at the other sites. The corrected results for the first seven months of monitoring are shown in the following table.

Concentrations are shown to exceed the annual mean AQS objective at sites 12, 13 and 14, the Trinity Foot Public House and 5m and 10m from the edge of the A14 in transect respectively. Concentrations at all other sites were below the AQS objective, although marginally so at the Bar Hill monitor and Cambridge Roadside monitor. A report will be issued following completion of the monitoring survey.

SUMMARY

Concentrations of 1,3-butadiene, benzene and carbon monoxide are expected to achieve their respective AQS objectives throughout the study area. There are numerous exceedences of the annual mean NO2 objective, especially at roadside sites, indicating that concentrations are likely to be sensitive to any changes in traffic flows. The hourly NO2 objective was exceeded at one site close to the A14 in 2003. The annual mean PM10 AQS objective was achieved, but the 24-hour objective was exceeded at two sites close to the A14 in 2003.

2 (Ref: Local Air Quality Management: Technical Guidance LAQM.TG(03), Defra, 2003)

Table 4.8 - Bias Adjusted Nitrogen Dioxide Monitoring Results (µg/m3)

4.3.4 Methodology

APPROACH TO ASSESSMENT

The assessment was carried out in accordance with the Design Manual for Roads and Bridges (DMRB) Volume 11 section 3, part 1, air quality, revision February 2003 and Transport Analysis Guidance (TAG) The Local Air Quality Sub-objective Unit 3.3.3, February 2004. The scheme has been assessed in terms of

A constraints map showing areas within 200m of roads affected by the scheme, which may experience changes in air quality;
A Local Impact Assessment comprising estimated pollutant concentrations at selected properties in relation to the relevant criteria;
An assessment of the overall change in exposure to concentrations of NO2 and PM10 following guidance in the DfT's TAG, the TAG Assessment

CONSTRAINTS MAP

A constraints map was drawn to show areas within 200m of the roads affected by the proposed improvements that are likely to have a change in air quality. This allows identification of the number of properties where people are likely to be subjected to a change in air quality, the identification of sensitive properties and properties likely to experience higher than average pollutant concentrations at locations such as road junctions. Sensitive properties include those where there may be vulnerable occupants, such as schools, hospitals or homes for the elderly. The following table displays the type and number of sensitive properties identified within 200m of the A14 and affected roads.

Table 4.9 - Number of Sensitive Properties Identified in the Vicinity of the A14 and Affected Roads
Type of Sensitive Receptor	Number within 200m of A14 and Affected Roads
Care Home	1
Clinic	7
Hospice	2
Hospital	5
School	60
Surgery	29

LOCAL AIR QUALITY IMPACT ASSESSMENT

The DMRB states that the screening method should be used to estimate concentrations of carbon monoxide, nitrogen dioxide, benzene, 1,3-butadiene and particulate matter (PM10) to compare with AQS objectives. However, the assessment focuses in particular on the pollutants NO2 and PM10 as the air quality criteria for these two pollutants are likely to be most difficult to achieve in the vicinity of roads. Predictions were made both with and without the proposed A14 improvements, termed the scheme and do-minimum respectively. The years selected for assessment were the existing case (2003), and the opening year (2010).

4.3.5 Alternative Proposal

The assessment was carried out for the Alternative Proposal (a limited junction option) and a Do Minimum.

The study area for the air quality assessment has been defined based on the change in traffic on the road network. Additional traffic is expected to be induced on the off-line section of the A14 and the pattern of traffic flow on the road network will be affected by the increased capacity of this road.

A large number of road links are within the study area. DfT's TAG states "options which change traffic flows by less than 10% can usually be scoped out, unless the road is a motorway or there are particular sensitivities". On this basis the network for the air quality assessment included all existing and new alignments of the A14, and all other roads with flows of greater than 5,000 vehicles per day which experience an increase or decrease in traffic of greater than 10% with any of the traffic options.

The road network assessed for the study area is illustrated in the air quality constraints map.

Receptor Selection

Usually, a number of specific properties or receptors are chosen for assessment. However, for this assessment, as the study area under consideration was so large, Ordnance Survey Address-Point® data was used to pinpoint the location of residential properties. For each property, the Address-Point® dataset contains a unique identifier, national grid reference and postal address. When identifying properties from maps without address point data, accidental consideration of structures not used for occupancy by people can occur. Using Address-Point® data ensures only buildings with a postal address are included in the count. The data also contains a field for business name which is used to screen the data to remove business addresses.

The use of an access database enabled the pollutant concentrations at all properties within 200m of the scheme and affected roads to be calculated. In addition to residential properties, the effect on air quality at schools and other sensitive properties within 200m of affected roads can be assessed. Concentrations at properties near the junctions on the A14 were calculated using the DMRB spreadsheet rather than the database, due to the complexity of the junctions.

Comparison of Modelled and Monitored Concentrations

To provide some validation of the concentrations predicted using the DMRB, a comparison of estimated and measured concentrations was undertaken for NO2 and PM10 at the location of continuous monitoring stations close to the A14.

The DMRB screening method was used to calculate concentrations at the local authority continuous monitoring sites at Bar Hill, Godmanchester and Impington.

In addition, the DMRB screening method was used to calculate concentrations at the locations of the nitrogen dioxide diffusion tube survey being carried out by Atkins. Data from the first seven months of the survey, adjusted for bias, was used to compare with the estimated results.

TAG Assessment

This assessment gives a quantitative indication of whether the scheme would lead to an overall improvement or deterioration in air quality at properties and is based on the DfT's Transport Analysis Guidance (TAG) The Local Air Quality Sub-Objective Unit 3.3.1, February 2004.

Pollutant concentrations decrease with increasing distance from the traffic, therefore concentrations are calculated at 20 m, 70 m, 115 m and 175 m from the road centre, with and without the proposed scheme, for each route option.

The number of properties in 50 m bands from the centre of each road link was counted out to a distance of 200 m for the do minimum and scheme scenarios. The Address-Point® dataset, described above, and a geographic information system was used to facilitate this. The number of properties in each band is multiplied by the concentration calculated for that band for the do minimum and scheme scenarios. This is carried out for each of the four bands and the results added together to give a total for each scenario. The do-minimum value is deducted from the scheme value for each affected route. The overall assessment score is calculated by summing values over all routes, with an improvement (decrease in concentrations) having a negative value and a deterioration (increase in concentrations) having a positive value.

RESULTS

Local Air Quality Impact Assessment

Pollutant concentrations at properties within 200m of the existing and new alignments of A14 and other roads affected by a significant change in traffic due to the scheme have been calculated. This area includes some 65,000 properties.

Due to the large number of properties assessed, it has not been possible to report the predicted concentrations at each. Instead, the concentrations have been compared with the AQS objectives to determine whether any exceedances have been predicted and the magnitude of any changes in concentrations analysed.

Exceedances of AQS Objectives

In 2010 the AQS objectives for all pollutants are expected to be achieved at all receptors with the Alternative Proposal. Some exceedances of the provisional 2010 annual mean PM10 objective were predicted in Cambridge. Approximately 28 properties are expected to exceed this provisional objective with the Do-Minimum, and 21 properties with the Alternative Proposal.

Changes in Concentrations at Receptors

The following tables give details of the maximum concentrations and greatest changes predicted at receptors for NO2 and PM10 respectively.

Table 4.10 - Maximum Concentrations and Greatest Changes in Concentrations for NO2 (µg/m3)
Traffic Option	Maximum Conc.	Greatest Increase	NO2 (µg/m3) Traffic Option Maximum Conc. Greatest Increase No Properties with Change >4	Greatest Decrease	No Properties with Change <-4
BASE	42
Do Minimum	33
Alternative Proposal	31	7.84	4	-8.72	27

Table 4.11 - Maximum Concentrations and Greatest Changes in Concentrations for PM10 (µg/m3)
Traffic Option	Maximum Conc.	Greatest Increase	NO2 (µg/m3) Traffic Option Maximum Conc. Greatest Increase No Properties with Change >2	Greatest Decrease	No Properties with Change <-2
BASE	30
Do Minimum	22
Alternative Proposal	21	2.28	1	-3.15	2

There are expected to be both increases and decreases in concentrations at receptors with the scheme.

With the Alternative Proposal there are 4 properties with an increase in annual mean NO2 concentrations of greater than 4µg/m³, and 27 properties with a decrease in annual mean NO2 concentrations of greater than 4µg/m³. The greatest increase for NO2 with the scheme is 8µg/m³, and the greatest decrease is 9µg/m³.

For PM10 there is 1 property with an increase in annual mean concentrations greater than 2µg/m³ and 2 properties expected to have a decrease in annual mean PM10 concentrations of greater than 2µg/m³ . The greatest increase for PM10 is 2µg/m³, and the greatest decrease with the scheme is 3µg/m³.

Junction Options

Annual mean concentrations of NO2 and PM10 at 14 receptors near junctions on the proposed and existing alignments of the A14 for the alternative proposal are shown in the Environmental Assessment Report Addendum.

None of the concentrations predicted at the receptors are expected to exceed any of the AQS objectives in 2010 with or without the scheme. The majority of receptors are expected to have similar concentrations with both scheme options, the one exception being Hackers Fruit Farm, where concentrations differ due to the traffic flows associated with the proposed local access road.

For NO2 the greatest increase at any receptor is 6.3 µg/m³ at Little Cottage, as the proposed route passes close to this receptor.

Concentrations at Grafham Road Cottages, Depden Farm, Rectory Farm, Tree Avenue and Impington Farm are expected to have increases of 4.8, 4.1, 4.0, 4.0 and 3.4 µg/m³ respectively. Increases at all other receptors are expected to be less than 3 µg/m³.

The greatest decreases with the scheme proposal are expected to occur at the 8 additional receptors affected by the Alternative Proposal between Ellington and Fenstanton. These include a decrease of 13.1 µg/m³ for 28 Greendale, 10.4 µg/m³ for Rectory Farm near Godmanchester Junction, 10.3 µg/m³ for 52 Cambridge Villas and 9.2 µg/m³ for the Motel at Fenstanton. At the other receptors (Meadow View Farm, 17 Lodge Close, 9 Laurel Court and 51 Pitfield Close) concentrations are expected to decrease by 3-4 µg/m³.

The changes in concentrations for PM10 follow the same pattern as for NO2. The greatest increases for PM10 are at Little Cottage, Depden Farm, and Tree Avenue with increases of 2.1, 1.3, and 1.1 µg/m³ respectively. The greatest decreases are expected to occur at the receptors affected by the Alternative Proposal between Ellington and Fenstanton. Decreases range between 1.1 and 7.4 µg/m³. All other receptors are expected to have a negligible change.

Generally the concentrations predicted for the Alternative Proposal options are slightly higher than those for the CHUMMS Strategy orange route options at all receptors; with concentrations up to 5 µg/m³ higher for nitrogen dioxide, and 2 µg/m³ higher for PM10.

4.3.6 Comparison of Modelled and Monitored Concentrations

CONTINUOUS MONITORING SITES

The results of the comparison of modelled and monitored concentrations for 2003 are shown in the following table.

Table 4.12 - Comparison of Modelled and Measured Concentrations (2003)
Site	Source Roads	Pollutant	Predicted Annual Mean	Measured Annual Mean	Difference (%)	Difference (µg/m3)
Bar Hill	A14	NO2	37	50	26	13
Bar Hill	A14	PM10	23	33	30	10
God-manchester	A14, B1044	NO2	38	40	5	2
God-manchester	A14, B1044	PM10	24	29	17	5
Impington	A14	NO2	35	52	33	17
Impington	A14	PM10	22	39	44	17

The results indicated that at Bar Hill and Impington there was an under prediction in modelled concentrations of NO2 and PM10 compared to the measured concentrations of around 30%. Average factors of 1.3 and 1.5 for NO2 and PM10 respectively, were derived. Meteorological conditions in 2003 were largely responsible for poorer air quality in this year than in previous years, hence concentrations were also estimated for 2002 using the 2003 traffic data, and compared with the monitoring data for 2002, shown in the following table.

Table 4.13 - Comparison of Modelled and Measured Concentrations (2002)
Site	Source Roads	Pollutant	Predicted Annual Mean	Measured Annual Mean	Difference (%)	Difference (µg/m3)
Bar Hill	A14	NO2	38	42	9	4
Bar Hill	A14	PM10	23	30	22	07
God-manchester	A14, B1044	NO2	39	39	0	0
God-manchester	A14, B1044	PM10	24	20	-22	-4
Impington	A14	NO2	36	53	32	17
Impington	A14	PM10	22	30	26	8

In 2002 there is still an under prediction in modelled concentrations of NO2 and PM10 compared to the measured concentrations. However, at Godmanchester the modelled concentrations are more comparable. At Impington there is still an under prediction of around 30%, and at Bar Hill the under prediction is around 15-20%. Average factors of 1.2 and 1.1 for NO2 and PM10 respectively, were derived.

When receptor concentrations in 2010 are multiplied by these factors there will still be no exceedances of annual mean AQS objective for either NO2 or PM10. However, with the 2003 adjustment factors, concentrations of NO2 may exceed the annual mean AQS objective at a small number of receptors with the Do Minimum. The majority of these receptors are located in Cambridge. However, there are some receptors located in the vanity of the A14 which are expected to exceed the objective with the Do Minimum. These receptors are given in the following table.

Table 4.14 - Properties Exceeding the Annual Mean NO2 AQS Objective in the Vicinity of the A14
Traffic Option	Properties
Do Minimum	Crouchfield Villa, Hackers Fruit Farm, Huntingdon Road & Cambridge Road, Orthwaite, Huntingdon.
Alternative Proposal

Diffusion Tube Survey

Nitrogen dioxide results estimated using the DMRB have also been compared with the monitoring data from the diffusion tube survey carried out by Atkins. The results of the comparison are presented in the following table.

Table 4.15 - Comparison of NO2 Concentrations with Diffusion Tube Survey Results
Site No	Location	Modelled Concentration	Monitored Concentration	Difference µg/m3	% Under/ Over Estimation
1,2,3	Cambridge Continuous monitor	29.8	37.2	-7.4	-24.8%
4	Impington Continuous monitor	38.6	25.5*	13.2	34.1%
5	Brampton Lodge	22.1	18.0	4.1	18.4%
6	Thrapston Road, Brampton	33.9	27.1	6.8	20.1%
7	Depden Farm	20.2	17.5	2.8	13.6%
8	Castle Hills, Huntingdon	28.9	27.9	1.0	3.5%
9	Cambridge Villas, Godmanchester	33.1	25.2	7.9	23.7%
10	Rectory Farm	36.9	28.9	8.0	21.6%
11	Gore Tree Farm	29.2	28.2	1.1	3.6%
12	Trinity Foot PH	35.8	44.7	-8.8	-24.6%
13	Transect 5m	35.9	55.8	-19.9	-55.4%
14	Transect 10m	34.3	49.1	14.8	-43.0%
15	Transect 50m	26.4	35.0	-8.7	-32.9%
16	Transect 130m	21.1	26.2	-5.1	-23.9%
17	Acorn Ave, Bar Hill	22.0	27.4	-5.4	-24.3%
18	Bar Hill monitor	34.6	39.3*	-4.7	-13.6%
19	Cambridge Road, Girton	31.8	20.8	11.0	34.7%

* Comparison of the results has taken place with the diffusion tube at this location. Comparison will also take place with the data from the continuous monitor when this becomes available

The results show that there is an overall variation of +35% and -50% between the concentrations modelled and monitored. At two rural locations, where there are no road sources within 200m (Brampton Lodge and Depden Farm the background concentrations taken from the 1km grid squares which are provided in the Air Quality Archive were higher than those measured using diffusion tubes (22µg/m3 and 20µg/m3 compared to 18µg/m3 and 18µg/m3 respectively). This suggests that at rural locations, the DMRB method may be overestimating by up to 20% due to background concentrations used. However, as the concentrations at these sites are well below the AQS objective, this is unlikely to have any significant consequences.

At the other extreme, concentrations are being under estimated by the DMRB by up to 55% at the closest points to the A14, 5 and 10m from the edge of the carriageway. It is not certain why this underestimation is occurring; it may be as a result of the prevailing wind direction which the DMRB does not take into account. At other locations, estimated concentrations are within ±35% of the measured data (which can be considered a reasonable estimate). Overall, the model was found to be under estimating by around 5%.

4.3.7 TAG Assessment Results

The results of the TAG assessment are summarised in the following table.

The assessment of the Alternative Proposal shows that there is an overall increase in PM10 and NO2 concentrations at the properties near the off-line section of the A14. In the wider network, there is expected to be a large decrease overall in both PM10 and NO2 concentrations, which outweighs the increase near the off-line section.

The overall assessment shows that the scheme will lead to an improvement in both PM10 and NO2 concentrations at affected properties compared to the Do Minimum.

Table 4.16 - TAG Assessment Results
Pollutant	PM10 Assessment	No. Properties with Improvement	No. Properties with No Change	No. Properties with Deterioration
PM10	-950	18,982	0	2,122
NO2	-3,442	18,846	0	2,258

4.3.8 Comparison of the Alternative Proposals with the CHUMMS Strategy

CHANGES IN CONCENTRATIONS

The following two tables compare the maximum concentrations and greatest changes predicted at receptors for NO2 and PM10 respectively, for the CHUMMS Strategy and Alternative Proposal.

The maximum predicted concentrations of NO2 and PM10 are the same for both the Alternative Proposal and the CHUMMS Strategy. Fewer properties are expected to experience a change in NO2 concentrations of greater than ±4 µg/m3 for the Alternative Proposal. Similarly for PM10 there are expected to be fewer properties expected to experience a change in concentrations of greater than ±2 µg/m3 for the Alternative Proposal.

With the CHUMMS Strategy, the largest decrease in concentrations is significantly greater for both pollutants than with the Alternative Proposal. This is a result of the improvements along the Huntingdon Viaduct section.

Table 4.17 - Maximum Concentrations and Greatest Changes in Concentrations for NO2 (µg/m3)
Traffic Option	Maximum Conc.	Greatest Increase	No Properties with Change >4	Greatest Decrease	No Properties with Change <-4
CHUMMS Strategy	31	5.4	69	-15.5	95
Alternative Proposal	31	7.84	4	-8.72	27

Table 4.18 - Maximum Concentrations and Greatest Changes in Concentrations for PM10 (µg/m3)
Traffic Option	Maximum Conc.	Greatest Increase	No Properties with Change >2	Greatest Decrease	No Properties with Change <-2
CHUMMS Strategy	21	<2	0	-6.2	37
Alternative Proposal	21	2.28	1	-3.15	2

The following two tables compare the changes in concentrations at 20m (taken from the TAG assessment) between the CHUMMS Strategy and Alternative Proposal through the Huntingdon Viaduct and along the New A14 alignment, south of Godmanchester, the key areas where there are differences between the options.

Table 4.19 - Comparison of Changes in Concentrations at 20m from the Road Centre through Huntingdon Viaduct (µg/m3)
Pollutant	CHUMMS Strategy	Alternative Proposal	Difference
NO2	-6.4	-3.5	2.9
PM10	-2.7	-0.8	1.9

Table 4.20 - Comparison of Changes in Concentrations at 20m from the Road Centre Along New A14 Alignment South of Godmanchester (µg/m3)
Pollutant	CHUMMS Strategy	Alternative Proposal	Difference
NO2	13.0	12.1	-0.9
PM10	4.8	4.0	-0.8

TAG ASSESSMENT

A comparison of the results for the Alternative Proposal with the CHUMMS Strategy previously assessed was made. A comparison of the TAG assessment scores are given in the following two tables.

Table 4.21 - PM10 Assessment
Option	PM10 Assessment	No. Properties with Improvement	No. Properties with No Change	No. Properties with Deterioration
CHUMMS Strategy	-525	20,665	0	9,041
Alternative Proposal	-950	18,982	0	2,122

Table 4.22 - NO2 Assessment
Option	PM10 Assessment	No. Properties with Improvement	No. Properties with No Change	No. Properties with Deterioration
CHUMMS Strategy	-1,731	19,528	0	10,178
Alternative Proposal	-3,442	18,846	0	2,258

The CHUMMS Strategy is expected to result in a greater improvement on the existing road network than the Alternative Proposal. However the Alternative proposal will have a much smaller deterioration in air quality at properties in the vicinity of the new A14 route alignments than the CHUMMS Strategy. The overall assessment scores indicate that the Alternative Proposal is expected to result in a greater improvement in air quality than the CHUMMS Strategy.

The total number of properties affected is expected to be smaller for the Alternative Proposal. The Alternative proposal will result in a similar number of properties having an improvement in air quality, but there will a lot fewer properties with a deterioration in air quality than for the CHUMMS Strategy.

4.3.9 Conclusions

The Stage 2 air quality assessment has consisted of examining existing conditions, assessing the change in concentrations at properties likely to be affected by the proposed scheme options, and undertaking an overall assessment of exposure according to the TAG methodology.

Measured concentrations of annual mean nitrogen dioxide are expected to exceed the AQS objective near roadside sites in the study area, as well as near the A14. Concentrations of PM10 also exceeded the 24-hour mean objective at sites near the A14, although concentrations were below the annual mean objective.

Concentrations of carbon monoxide, benzene and 1,3-butadiene are all well below their respective AQS objectives. Although there are no air quality management areas in the study area at present, detailed assessments are currently in progress, and it is likely that an AQMA will be declared in Cambridge city centre and around the ring road and associated feeder roads in Huntingdon.

The results of the local air quality assessment show that there are a small number of exceedances of the provisional 2010 annual mean PM10 AQS objective, with and without the scheme. None of the other AQS objectives are expected to be exceeded in the opening year based on raw modelling results.

There are expected to be both increases and decreases in concentrations at receptors with all scheme options. There are 4 properties with an increase in annual mean nitrogen dioxide concentrations of greater than 4µg/m³ and 27 properties with a decrease in annual mean nitrogen dioxide concentrations of greater than 4µg/m³ . The greatest increases for nitrogen dioxide with the scheme options are 8µg/m³, and the greatest decreases between 8 and 9µg/m³. For PM10 there is 1 property expected to have an increase in annual mean concentrations greater than 2µg/m³. The greatest increase with the scheme is 2µg/m³. Two properties are expected to have a decrease in annual mean PM10 concentrations of greater than 2µg/m³. The greatest decrease with the scheme is 3µg/m³.

A comparison of modelled and measured data has been undertaken for the three continuous monitoring sites near the A14. Concentrations were compared to data in 2003, and due to the high concentrations experienced in this year, to data in 2002. Modelled concentrations in 2003 were shown to under estimate the measured concentrations at all three monitoring stations, by around 30%. Modelled concentrations in 2002 were still shown to underestimate those measured at the Bar Hill and Impington sites, although they were comparable at the Godmanchester site for nitrogen dioxide. By applying adjustment factors derived from the 2002 comparison, modelled concentrations are still expected to achieve the AQS objectives, although with the 2003 adjustment factors, annual mean concentrations of nitrogen dioxide may exceed the objective at a small number of receptors.

A comparison of the modelled results with the measured data from the Atkins diffusion tube survey suggests that concentrations are being over and underestimated by as much as 55%, although in general the range is largely within ± 35%. It is recommended that a detailed dispersion study is carried out, as with an underestimate of 30% this could lead to exceedances of the 2010 annual mean nitrogen dioxide objective.

The TAG overall assessment score shows that the scheme will lead to an improvement in both PM10 and NO2 concentrations at affected properties. There is an overall increase in PM10 and NO2 concentrations at the properties near the new alignment of the A14 with all of the options. In the wider network, there is expected to be a large decrease overall in both PM10 and NO2 concentrations, which outweighs the increase near the A14.

A comparison between the Alternative Proposal and the CHUMMS Strategy indicates that the Alternative Proposal is expected to result in a greater improvement in air quality than the CHUMMS Strategy as indicted by the TAG assessment. In addition there are expected to be fewer properties with large changes in concentrations of NO2 and PM10 (change of ±4µg/m3 for NO2, ±2µg/m3 for PM10.) as compared to the Do Minimum. However, the CHUMMS Strategy is expected to result in significantly greater improvements in air quality in the areas adjacent to the Huntingdon Viaduct due to significantly lower traffic flows through this section of the route with this option.

4. environmental assessment (continued)

4. Environmental Assessment (continued)

4.4 Land Use

4.4.1 Introduction

This chapter considers the characteristics of land affected by the options in terms of its quality and current use.

The impacts of the options are assessed for agricultural and other land uses, including local mineral workings, landfill sites, development land and existing residential dwellings are also assessed.

4.4.2 Non Agricultural Land Use

EXISTING CONDITIONS

Allocated Development Land

The majority of the study area comprises of Grade 2 and 3a agricultural land. The study area extends from Ellington, to the west of Huntingdon to Fen Drayton Interchange. A number of smaller settlements line the route corridor. These include in an east to west direction, Conington, Fenstanton, Hemingford Grey, Hilton, Godmanchester, Offord Cluny, Buckden and Brampton.

There are a number of significant developments located within the route corridor including the following:

Buckden landfill site, located between Buckden and Brampton,the northern part of which is currently active;
Wood Green Animal Shelter;
Beaconsfield Equestrian Centre;
Brampton Park Golf Course;
Hemingford Abbots Golf Complex;
There are a wide range of privately owned agricultural enterprises located throughout the study area.

Planning Applications

This Addendum uses information on planning applications/permissions obtained in January 2004 for locations adjacent to the road.

The following list outlines the principal on-going planning applications and development proposals made within the study area, as of January 2004:

A substantial area of land has been zoned for a new settlement of up to 10,000 houses at Longstanton/ Oakington which will generate significant traffic on the A14.
Permission has been granted for extraction of sand and gravel at Buckden Quarry, Huntingdon. It is expected that this site will be worked on over the next few years.
Planning permission was granted for the construction of 3 office buildings at Eden Park, West End Road, West End Farm, south west of Fenstanton.
Planning permission for a grain store at Topfield Farm, Cambridge Road, Hemingford Grey was granted in May 2003.
Planning permission was granted in 2003 for the construction of an indoor golf centre and extensions to clubhouse at Hemingford Driving range, Cambridge Road, Hemingford Abbots.
Planning permission was granted in 2003 for additional cattery buildings, kennels, reception areas, restaurant and a function hall at Wood Green Animal shelter, London Road, Godmanchester.
Planning permission was granted for a golf driving range building at Station Farm, Buckden Road, Brampton in October 2001.

Mineral and Waste Sites

Buckden North landfill site is the only active landfill site located within the study area. Buckden South landfill site, Hemingford Grey landfill site and Conington landfill site are all full.

An application for planning permission for mineral extraction by Lafarge Aggregates (H/5004/02/CM) has been submitted for a site east of Buckden. This application was recently granted consent.

A full review of the policies and objectives of the Cambridgeshire County Council Minerals Local Plan is included in 'Plans and Policies'.

Existing Dwellings

The Alternative Proposal traverses agricultural land. There are a number of farming enterprises and village settlements located within the vicinity of the route corridor. There are also a number of dwellings located in close proximity to the route option, particularly to the south of Brampton and in the vicinity of Fenstanton.

Huntingdon Viaduct

Land adjacent to the viaduct currently comprises land associated with the A14 and B1514 roads, Huntingdonshire railway station (including parking and access), and areas of open space and scrubland. Views Common is situated towards the north-west; Mill Common is located towards the south-east.

Based on discussions with Planning Officers at Huntingdonshire District Council, it is understood that there are no outstanding planning permissions or applications within the immediate vicinity of the viaduct. Similarly, according to the most updated version of the Local Plan, there is no land adjacent to the viaduct allocated for development purposes.

POTENTIAL IMPACTS

The Alternative Proposal would traverse a site on which a planning application for mineral extraction has been approved.

The route traverses open countryside, creating a barrier between village settlements located to the north and south. However, this barrier would not be any greater to that which is already created by the existing A14. Mitigation measures in the form of over/ under-bridges would allow unrestricted movement between these settlements, thus minimising the degree of severance.

In relation to the viaduct, land take and road closures associated with the construction phase would conflict with adjacent land uses in the short term.

COMPARISON WITH CHUMMS STRATEGY

The differences in impacts between the CHUMMS Strategy and the Alternative Proposal would be negligible in land use terms. A reduced area of land take associated with the Alternative Proposal could slightly reduce conflict with the area of land subject to the minerals extraction (east of Buckden).

The construction phase (Alternative Proposal) associated with the viaduct replacement would cause disruption to adjacent land uses in the short term. The CHUMMS Strategy would encroach into Mill Common (protected open space) in the longer term, during both the construction and operational phases.

The construction phase associated with the viaduct replacement (Alternative Proposal) would cause disruption to adjacent land uses in the short term. The CHUMMS Strategy would encroach into Mill Common in the longer term, during both the construction and operational phases.

4.4.3 Agricultural Land Use

INTRODUCTION

Most of the land affected by the A14 improvement is agricultural. Accordingly, an assessment has been made here of the potential impact on agricultural resources and existing farm businesses.

This Stage 2 assessment considers the characteristics of agricultural land affected by the off-line sections of the Alternative Proposal in terms of its quality and current use. The likely impacts on affected holdings are assessed and recommendations made concerning mitigation measures. Impacts are assessed with and without recommended mitigation measures being implemented and the assumption is that, in broad terms, the agricultural circumstances prevailing at the time of survey will continue to prevail. However, it should be noted that the recent Mid-term Review of the Common Agricultural Policy, with its far reaching reforms of agricultural support systems, may have dramatic but, as yet, largely unpredictable effects on the rural economy.

In the final section, the off-line Alternative Proposal is compared with the CHUMMS Strategy.

No detailed analysis is presented here of the agricultural impacts of the scheme along the existing A14 between Fen Drayton and the Spittals Interchange. This is because there is no agricultural land take and the only impact will be the closure of farm and field accesses off the A14 and their replacement with accommodation tracks from the junctions. These new access arrangements will be safer than the present arrangements and so the impact of the scheme in this section will be neutral or slightly beneficial.

Reconstruction of the Huntingdon Viaduct will have no impact on the adjacent grazing meadows of Mill Common and Views Common.

METHOD

Legislative Requirements

The 1999 "Town and Country Planning (Environmental Impact Assessment) (England and Wales) Regulations" state that an EIA, including an agricultural assessment, where appropriate, is required for projects of this nature.

This agricultural assessment has involved the study of client-supplied data and original survey work. It should be noted that TAG, with its use of Assessment Summary Tables, has not been adapted to agricultural studies and so this report follows the DMRB Volume 11 Guidelines for a Stage 2 Environmental Assessment.

The four main areas covered in any assessment of the effects of a new road on agricultural land are specified as:

Land take in relation to quality and quantity of agricultural land lost
Type of husbandry
Severance
Major accommodation works

National Policy

Planning policy regarding agricultural land in England is set out in PPS7 (The Countryside: Environmental Quality and Economic and Social Development), concerning sustainable development in rural areas. This states that, where possible, development should not take place on land in Grades 1 - 3a (best and most versatile), according to MAFF's 1988 Revised Guidelines for Agricultural Land Classification of England and Wales. It also requires assessments to take into account the impact of a proposed development on farm size and structure and any buildings and fixed equipment.

SURVEY AND DATA COLLECTION

Prior to conducting field surveys, published and unpublished data and route plans were consulted. The route corridor was examined in the field between October 2003 and January 2004. Surveys comprised:

Assessment of soils.
Interviews.
Route examination: either during or after interviews, the route was examined in order to verify details discussed at the interview, and to examine land use and condition. Agri-Environmental grant schemes.

METHOD OF ASSESSMENT

The methods of assessing the relative degree of impact are described in greater detail at the relevant part of the text. However, the general methodology can be summarised as follows:

Land Take: this is assessed in terms of quantity and quality, and the losses evaluated against national and local criteria.
Farming practice: the methods of working of individual farms are described, and the impact of the proposals assessed.
Access: the effect on access both into and out of farms and internally within units is described.
Economic impacts: the effect of the proposed routes are described and assessed in terms of broad economic impact. Comparative assessments have been made to evaluate the order of magnitude of the impact. These are for comparative assessment purposes only, using standardised data, and do not necessarily reflect accurately the potential financial losses on each farm. It should be noted that the purpose of this assessment is to indicate the severity of impact and not to evaluate levels of compensation payable.
Other effects: these include drainage, prospects for farm-based diversification, sporting and other interests or effects as identified during this assessment.

BASELINE SITUATION

Existing conditions immediately prior to the proposed development (the baseline situation) can be divided into two categories:

Inherent conditions not influenced by man to a significant degree; and
Land use conditions reflecting man's use of natural resources. These are generally of a more short-term nature.

Inherent Conditions

The inherent conditions include the geology, the relief or topography of the area, the climate and the character and quality of the soils.

The basic geology of the area has been described in Part I of the SAR. The EAR chapter on agriculture described the geology of the route corridor, relevant to the understanding of soils and Agricultural Land Classification.

The land falls away northward and eastward to the Ouse and Cam valleys. East of Hilton the landscape of the route corridor is below 20 m O.D. and nearly level, consisting of Oxford Clay, terrace deposits and alluvium. This flat landscape merges almost imperceptibly with the flat fens north of the route corridor.

The climate is one of the driest in Britain with only 560 mm of rainfall annually on the high ground and around 520 mm on the low ground.

Soils

The Soil Map of Eastern England with its accompanying book is a generalised soil map that lacks field by field detail. However, it does provide a useful introduction to the broad pattern of soils, indicating areas of lighter, better quality land in what is a landscape of predominantly heavy soils in Jurassic Clay and Chalky Till. Other map sources provided greater detail in localised areas.

Soil surveys were carried out as part of this assessment along the line of the route options in areas where the level of published information is insufficient for the purposes of Agricultural Land Classification. Government policy, as set out in PPG7, is designed to protect the best and most versatile land, normally Grades 1, 2 and 3a. The published MAFF 1:250,000 Agricultural Land Classification Map of Eastern England provides only a broad indication of land quality and should not be used definitively on specific sites smaller than 80 ha in size. Moreover, the published Defra map does not subdivide Grade 3 into 3a and 3b and so cannot be used definitively in areas that are marginal to best and most versatile. The study area is shown as an area of Grade 2 and 3 land of good to moderate quality and there is no published information available that subdivides the Grade 3 land of the district into 3a and 3b, according to the 1988 MAFF Agricultural Land Classification (ALC) of England and Wales: Revised Guidelines and Criteria for Grading the Quality of Agricultural Land.

The DMRB recommends that where more than 20 ha of best and most versatile land in Grades 1 - 3a are likely to be lost to agricultural production, Defra should be consulted as to whether a more detailed survey is needed. Such a survey, encompassing soils, climate and topography, would be carried out according to MAFF's 1988 Revised Guidelines for the Grading the Quality of Agricultural Land, which also provides the criteria for sub-dividing Grade 3 into 3a and 3b. Recent reorganisation of government responsibilities for rural development means that the consultee is now the Rural Affairs Team of the Regional Government Offices, rather than Defra.

For this assessment, detailed surveys were carried out in areas where the level of detail in the published information is not adequate to make an informed judgement of whether the land is likely to be Grade 3a or better. These were restricted to offline sections of the route options. In the on-line sections, the relatively small amount of land take and greater importance of engineering considerations mean that land quality is not a significant issue in road design. Also, it is very difficult to assess the ALC of land alongside a trunk road because of the presence of ditches, hedges, farm tracks and buried infrastructure.

Hanslope soils, being in Wetness Class II - Ill and having calcareous topsoils, are in Grades 2 or 3a and so additional surveys were considered unnecessary for this assessment. The Hanslope association may include poorer quality, decalcificied soils but typically these occur on the level sites on the main boulder clay plateau, well beyond the southern boundary of the route corridor.

Sutton and Efford soils can be short of moisture in summer, but existing 1:25,000 scale mapping of OS Sheet TL26 (Papworth Everard) showed that most of this land is in Grade 3a. Farmers are able to compensate for the moisture shortage by growing early maturing varieties of cereals and also benefit from the ability to grow spring sown crops in a district in which winter cropping predominates. Up until the 1970s these soils around Fenstanton and Brampton were noted for fruit production and market gardening.

Fladbury soils on floodplains are in Grade 3b and 4 because of wetness and the frequency of flooding.

The focus of soil surveys for this assessment was the area of land containing Evesham soils. Here, the soils have the potential to be Grade 2, 3a or 3b depending upon the clay and calcium carbonate content of the topsoil and the Wetness Class (as indicated by depths to gleying and a slowly permeable horizon). Soils were examined at 100 m intervals along the route lines, with a hand auger.

Soils were allocated to Grade 2, 3a and 3b, according to the profile characteristics identified in the following table. In terms of climatic data relevant to the classification, all the study area has fewer than 126 field capacity days (when the soil profile is replete with moisture).

Grade	Soil Characteristics
2	Wetness Class II with medium clay loam or calcareous heavy clay loam or calcareous clay topsoils
3a	Wetness Class II with non-calcareous heavy clay loam or clay topsoils Wetness Class III with calcareous heavy clay loam or calcareous clay topsoils
3b	Wetness Class III and IV with non-calcareous heavy clay loam or non-calcareous clay topsoils

LAND USE CONDITIONS

Land Use

This is a predominantly arable area characterised by mainly large farms. Nearly half of these farms are tenanted and owned by large institutions, including Cambridge University colleges. Many agricultural holdings are uninhabited outliers of larger farms, some of which are outside the study area. The main crops are those associated with heavy land rotations, typically winter wheat with beans and oil seed rape. Even on patches of lighter soils the rotations do not change significantly. There is a small amount of grassland, with a beef herds at Conington and Brampton and some pony paddocks, particularly around the towns and villages. There are several orchards and a soft fruit grower at Fenstanton. No irrigation was recorded, except at Fenstanton.

Many of the farms have shoots and so game covers are an important landscape feature. However, no commercial shoots are directly affected by the route options.

Land Values

All that can be said at this point in time, and this is largely conjectural, is that a block of arable land would be expected to sell for between £7,500 and £10,000 per hectare. However, a block of land suitable for pony paddocks, close to Huntingdon or the larger villages could go for a far higher sum.

Agricultural Holdings Affected

A total of 29 agricultural holdings are affected by the Alternative Proposal. The boundaries of the holdings are shown in Figure 9.6, EAR Volume.

Twelve of these holdings are tenanted and often form part of a larger farming enterprise. Others are farmed under contract by neighbours or contract farming companies and this is an increasing trend as farmers dispose of labour and machinery to reduce costs.

Arable farm sizes are typically in the range of 100 ha to 500 ha. Holdings smaller than 50 ha, or so, are generally classed as part time enterprises in that the owner relies on additional sources of income, such as contracting.

POTENTIAL IMPACTS - PERMANENT AND LONG TERM

This section describes the impacts of the A14 improvement that could be long term or permanent unless mitigation measures are designed into the scheme. Likely short term construction impacts are summarised in a later section.

Impacts that are irreversible and permanent are:

Loss of agricultural land to road construction and associated works such as balancing ponds and landscaping.
Some impacts that are long term may, in time, become less significant as patterns of farm ownership and management change. These include:
- Severance and loss of access
- Disruption to drainage
- Cumulative impacts resulting from reductions in farm size and/or manageability and/or income as a result of land take, severance or loss of buildings

Cumulative Impacts on Farm Viability

For each route option the impact on affected holdings has been assessed to determine the cumulative effects of land loss, severance and disruption to management.

All impacts apart from land take can, in theory, be mitigated. However, some severed parcels of land are too small to justify the cost of providing alternative access. Overall impacts on the agricultural enterprise are assessed both with and with out the proposed mitigation, so in most cases the main long term impact is that resulting from loss of land and disruption due to the division of the farm by the road scheme.

All agricultural impacts of this scheme are adverse and are graded on a scale from slight to major, as shown in the following table.

Table 4.24 - Scale of Farm Impacts
Impact	Description of Impact Grade
Slight adverse	The farm will experience only minor disruption, or a decrease in land area and/ or potentially profitability of less than 2%
Minor adverse	Land loss or disruption to the farm will affect the land area and/ or the potential profitability of the holding by 2% - 5%
Moderate adverse	Land loss or disruption to the farm will affect the land area and/ or potential profitability of the holding by 55 - 10%
Major adverse	There will be severe disruption to farming practice and the way the farm is managed. Land area and/ or profitability will be reduced by more than 10%

POTENTIAL IMPACTS - CONSTRUCTION PHASE

This section summarises the potential impacts at the construction phase. They are not covered in detail here as they will be the subject of investigation in Stage 3. The construction phase covers the period of the initial erection of fencing and defining the way leave area, through to completion of all post-construction boundary repairs, replanting and landscaping works.

Some of the impacts which occur during the construction stage, will become long-term ones. These include severance, water provision and drainage. The main construction phase impacts are:

Disturbance to soils and land for reinstatement
Construction severance
Loss of buildings
Damage to crops
Disturbance to livestock
Disease transmission
Field drainage and water supply
Disruption to field sports
Working camps, dumps etc

ALTERNATIVE PROPOSAL - PERMANENT AND LONG TERM IMPACTS

The permanent and long term impacts of the off-line sections of the Alternative Proposal on the farms through which they pass have been assessed and detailed schedules summarising the impacts are included within the EAR. The information covers:

Land take in hectares and as a percentage of the farm's area;
Loss of land in Grades 2 and 3a;
Main impacts and proposed mitigation; and
The scale of impacts before and after mitigation.

The impacts of the off-line sections of the Alternative Proposal are summarised below. This shows that nearly three quarters of the 178ha of land take is best and most versatile land in Grades 2 and 3a. Of the 29 affected working farms, 17 (59%) have cumulative impacts that are minor or slight while only three (10%) would suffer a major impact.

Table 4.25 - Alternative Proposal: Summary of Impacts on Agricultural Holdings
Total Land Take (ha)	Loss of Land in G2 - 3a in Off-line Sections (ha)	Farms Affected	Major Farm Impacts after Mitigation	Moderate Farm Impacts after Mitigation	Minor Farm Impacts after Mitigation	Slight Farm Impacts after Mitigation
178	132	29	3	9	10	7

COMPARISON WITH CHUMMS STRATEGY

A comparison of the Alternative Proposal with the CHUMMS Proposal is presented in table below. This shows that the total agricultural land take is reduced by 9ha (4.8%) under the former and the loss of best and most versatile land in Grades 2 and 3a is reduced by 6ha. The number of affected farms is the same, as is the relative distribution of cumulative farm impacts after mitigation. In terms of agriculture, therefore, the Alternative Proposal has a slightly lesser impact than the CHUMMS strategy, by reducing the total loss of farmland.

Table 4.26 - Comparison of Impacts of the Alternative Proposal and CHUMMS Strategy
Option	Total Land Take (ha)	Loss of Land in G2 - 3a in Off-line Sections (ha)	Farms Affected	Major Farm Impacts after Mitigation	Moderate Farm Impacts after Mitigation	Minor Farm Impacts after Mitigation	Slight Farm Impacts after Mitigation
CHUMMS Strategy	187	138	29	3	9	10	7
Alternative Proposal	178	132	29	3	9	10	7

SUMMARY OF AGRICULTURAL IMPACTS

This assessment has considered the long-term and permanent impacts of the Alternative Proposal on agricultural properties. The assessment was carried out in accordance with DMRB, using evaluation criteria that allow a comparative analysis of impacts. A number of impacts are long-term and can be mitigated as follows, by:

Minimising the effects of severance by providing alternative accesses as specified;
Minimising the land take for landscaping, particularly on Grade 2 and 3a land;
Monitoring off-site field drainage and making good, as necessary; and
Restoring water for livestock and irrigation, where supplies are severed.

A total of 29 working farms would be affected by the Alternative Proposal and the land take would be 178 ha of which 132ha are in the best and most versatile category (Grades 2 and 3a). After mitigation only three farms would suffer major impacts, due to land loss, and 17 would suffer only slight or minor impacts.

By comparison, the CHUMMS Strategy would take 187ha of which 138ha are in the best and most versatile category. The number of affected farms is the same, as is the number of farms suffering a major impact.

For the Alternative Proposal along the existing A14 between Fen Drayton and the Spittals Interchange there would be no loss of agricultural land. Existing farm and field accesses off the A14 would be replaced by a much safer arrangement of accommodation tracks from junctions and so the impact of the scheme is likely to be beneficial.

Highways Agency

Safe roads, Reliable journeys, Informed travellers

1. introduction

1. Introduction

1.1 Overview of Stage 2 Scheme Assessment Report Part I

1.2 Background and Objectives of Stage 2 Scheme Assessment Report Part II

1.3 Structure of the Report

2. scheme proposals

2. Scheme Proposals

2.1 Description of the CHUMMS Strategy

2.2 Description of the Alternative Proposal

2.2.1 A14 Mainline

2.2.2 Junction Strategy

2.3 Cost Estimate

2.3.1 Basis of Estimate

2.3.2 Comparison of Estimates

3. engineering assessment

3. Engineering Assessment

3.1 Introduction

3.2 Alternative Proposal

3.2.1 Mainline Alignment

3.2.2 Junctions

A1 BRAMPTON INTERCHANGE

FEN DRAYTON INTERCHANGE

GODMANCHESTER EMERGENCY ACCESS JUNCTION

3.2.3 Structures

EXISTING STRUCTURES

NEW STRUCTURES

RIVER GREAT OUSE VIADUCT

HUNTINGDON RAILWAY VIADUCT

3.2.4 Relaxations and Departures From Standards

3.2.5 Earthworks

3.2.6 Contaminated Land

3.2.7 Public Utilities

4. environmental assessment

4. Environmental Assessment

4.1 Introduction

4.1.1 Background to the Environmental Addendum to the SAR

4.1.2 Traffic Considerations for Environmental Assessment

4. environmental assessment (continued)

4. Environmental Assessment (continued)

4.2 Traffic Noise and Vibration

4.2.1 Introduction and Method of Assessment

NOISE

DESCRIPTIONS FOR THE MAGNITUDE OF EFFECT

STUDY AREA

TRAFFIC DATA

METHOD OF ASSESSMENT

LIMITATIONS

4.2.2 Baseline Conditions

GENERAL

AREAS ADJACENT TO THE EXISTING ROUTE

A14 between Ellington and A1 near Brampton

A1 South of the A14 Interchange

A14 between A1 near Brampton and A141 near Stukeley Junctions

A14 between A141 near Stukeley and A1198 Junctions

A1198 to A1096/B1040 Galley Hill Junctions

A1096/B1040 Galley Hill to west of B1050 Bar Hill Junctions

B1050 Bar Hill to M11 Interchange at Girton

A14 from Girton to B1047 Fen Ditton

AREAS ADJACENT TO CHUMMS STRATEGY

A14 between Ellington and A1 south of Brampton

A1 to Great Ouse Bridge near Offord

Offord to A1198 south of Wood Green Animal Shelter

South of Wood Green Animal Shelter to Fenstanton

Fenstanton to Bar Hill

CHANGES BETWEEN PRESENT AND OPENING YEAR (2010)

4.2.3 Key Issues/Areas

4.2.4 Mitigation Measures

4.2.5 Assessment of the two Options

DO MINIMUM

ROUTE OPTIONS

ASSESSMENT

OTHER AREAS AFFECTED BY NOISE CHANGES FROM TRAFFIC RE-DISTRIBUTION

CHUMMS Strategy

Alternative Proposal

4.2.6 Summary and Conclusions

EXISTING SITUATION AND DO MINIMUM

OPTIONS AND ASSUMPTIONS

GENERAL EFFECTS OF THE OPTIONS