A428 Black Cat to Caxton Gibbet improvements
TR010044 Volume 6 6.3 Environmental Statement Appendix 5.3: Air quality assessment methodology
Planning Act 2008 Regulation 5(2)(a) Infrastructure Planning (Applications: Prescribed Forms and Procedure) Regulations 2009
26 February 2021
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Infrastructure Planning
Planning Act 2008
The Infrastructure Planning (Applications: Prescribed Forms and Procedure) Regulations 2009
A428 Black Cat to Caxton Gibbet improvements Development Consent Order 202[ ]
Appendix 5.3: Air quality assessment methodology
Regulation Reference: Regulation 5(2)(a) Planning Inspectorate Scheme TR010044 Reference Application Document Reference TR010044/APP/) 6.3
Author A428 Black Cat to Caxton Gibbet improvements Project Team, Highways England
Version Date Status of Version Rev 1 26 February 2021 DCO Application
Planning Inspectorate Scheme Ref: TR010044 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Table of contents
Chapter Pages 1 Air quality assessment methodology 1 1.1 Model setup 1 1.2 Model outputs 4 1.3 Model post processing 28 1.4 References 37
Table of Plates Plate 1-1: Wind rose diagram for Luton Airport, 2015 ...... 3 Plate 1-2: Comparison of modelled NOX against monitored NOX in the ‘General’ zone prior to adjustment ...... 35 Plate 1-3: Comparison of modelled NOX against monitored NOX in the ‘General’ zone post- adjustment ...... 36
Table of Tables Table 1-1: General ADMS-Roads model conditions ...... 1 Table 1-2: Summary meteorological data for Luton Airport, 2015 ...... 3 Table 1-3: Public exposure receptors modelled in the local air quality assessment for the operation of the Scheme ...... 4 Table 1-4: Ecological receptors modelled in the local air quality assessment ...... 24 Table 1-5: Monitoring sites excluded from model verification ...... 30 Table 1-6: Monitoring sites used in model verification ...... 32 Table 1-7: Verification statistics ...... 34 Table 1-8: Verification details at monitoring sites ...... 34
Planning Inspectorate Scheme Ref: TR010044 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
1 Air quality assessment methodology
1.1 Model setup General inputs The parameters used within ADMS-Roads (Ref 1) are described in Table 1-1. Table 1-1: General ADMS-Roads model conditions
Variables ADMS-Roads model inputs
Emissions NOX, PM10
Emission factors IAN 185-13 Speed Band Emission Factors v2.3
Surface Roughness at source 0.5m
Minimum Monin-Obukhov length for stable 10m conditions
Meteorological data Hourly sequential data from Luton Airport in 2015
Receptors Selected representative receptors only. Identified from a combination of OS Mastermap and Addressbase data
Model Output Road contributions to long term annual mean NOX and PM10 concentrations
Additional input file Fac file for time varying emissions
A latitude of 52 degrees was input to the site data properties. This determines times of sunrise and sunset for each day throughout the year, which in turn affects stability calculations. A surface roughness coefficient of 0.5m (representative of parkland and open suburbia) was applied across the study area. The surface roughness is important in the approximation of turbulent conditions within the atmospheric boundary layer and thus in the estimation of pollutant concentrations at receptors. Minimum Monin-Obukhov length (to reasonably limit the occurrence of very stable atmospheric conditions) was defined as 10m at both the meteorological site and the dispersion site (representative of small urban areas). This parameter limits the occurrence of very stable boundary layer conditions (i.e. when the air is still) to a degree that is appropriate to the general land-use. In general, the potential for very stable conditions is lowest in large urban areas where the ‘heat island’ effect promoting turbulent motion in the boundary layer is strongest.
Planning Inspectorate Scheme Ref: TR010044 1 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Emissions rates The emission rates used in the local air quality modelling were derived from the Design Manual for Roads and Bridges (DMRB) LA 105 (Ref 2). In accordance with LA 105 the competent experts for traffic applied the following procedure: a. Analysis of the performance of modelled traffic speeds on individual road links compared against observed speeds on the same road links. b. Adjustment, where required, of modelled traffic speeds on individual road links to better reflect observed speeds; this is known as the ‘speed pivoting’ approach. c. Assignment of individual road links into a speed-banding category by road type. d. Manual adjustment, where required, of assigned speed band where changes in speed did not justify a change in speed band (e.g. speed changes of less than 5kph) or where a speed band change was considered by the traffic modellers to not reflect a valid Scheme impact. Hourly emission rates were then calculated as follows: a. Weekday morning peak (AM), inter peak (IP), evening peak (PM), off peak (OP) hourly flows (in terms of light duty vehicles (LDV) and heavy-duty vehicles (HDV)) and associated speed band for each road link were obtained from the traffic model for each period. b. The competent expert for traffic confirmed which hours the relevant traffic model periods apply to, as follows: i. AM: 07:00 – 10:00 (3 hours). ii. IP: 10:00 – 16:00 (6 hours). iii. PM: 16:00 – 19:00 (3 hours). iv. OP: 19:00 – 07:00 (12 hours). c. Emission rates for each time period were calculated using the using the traffic flow, %HDV, speed band and road type using the “IAN 185-13 Speed Band Emission Factors v2.3” spreadsheet tool. d. Emissions for each time period were input into the ADMS-Roads model and a “fac” file used to specify which hourly emission rate should be applied for each hour of the day. Meteorological data Hourly sequential meteorological data for 2015 for the Luton Airport meteorological station were used (Ref 2). The parameters required by the model included: date, time, wind direction (angle wind blowing from), wind speed (at 10m above ground level), surface air temperature (degrees Celsius), and cloud cover (oktas – or eighths of sky covered). Summary data for the site is presented in Table 1-2 and the wind rose for Luton Airport is presented below in Plate 1-1), indicating that the dominant wind direction for 2015 was from the southwest.
Planning Inspectorate Scheme Ref: TR010044 2 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
\\Ukcrd1fp001\ukcrd1fp001-v1ie\projects\general\AirPlate 1-1: Wind rose diagram Quality\Projects\A428 for Luton Airport, Black Cat\Modelling\Model_setup\Stacked 2015 method\Luton_15.met
350° 0° 10° 340° 800 20° 330° 30° 320° 40° 600 310° 50°
300° 60° 400
290° 70°
200 280° 80°
270° 90°
260° 100°
250° 110°
240° 120°
230° 130°
220° 140° 210° 150° 200° 160° 190° 180° 170° 0 3 6 10 16 (knots) Wind speed 0 1.5 3.1 5.1 8.2 (m/s)
Table 1-2: Summary meteorological data for Luton Airport, 2015
Parameter Value
Annual precipitation total (mm) No data
Calm (%) 1.6
Low wind speeds >0 ≤1.5 m/s (%) 6.4
Maximum Wind Speed (m/s) 18.0
Average Wind Speed (m/s) 4.7
Most frequent Wind Direction (deg) 210
Maximum Temperature (°C) 33.0
Minimum Temperature (°C) -4.0
Average Temperature (°C) 10.5
Average cloud (Octas) 4
Planning Inspectorate Scheme Ref: TR010044 3 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
1.2 Model outputs Public exposure receptors Table 1-3 presents details of the human health receptors included in the air quality model for the operation phase. The locations of these receptors are shown in Figure 5.3 of the Environmental Statement [TR010044/APP/6.2]. Table 1-3: Public exposure receptors modelled in the local air quality assessment for the operation of the Scheme
ID X Y Location Class type Local authority
Central Bedfordshire R1 498217 241457 The Woodlands Residential Council
Central Bedfordshire R2 498746 241560 Whittington Crescent Residential Council
Central Bedfordshire R3 499126 241745 Goodman Croft Residential Council
Central Bedfordshire R4 499346 241758 Arundel Road Residential Council
Central Bedfordshire R5 499707 242084 Barkers Piece Residential Council
Central Bedfordshire R6 499919 242484 Lower Shelton Road Residential Council
Central Bedfordshire R7 500023 242469 Lower Shelton Road Residential Council
Central Bedfordshire R8 500289 242767 Brooklands, Bedford Road Residential Council
R9 501787 245169 Stevenson Walk Residential Bedford Borough Council
Marsh Leys Cottages, Woburn R10 502436 245884 Residential Bedford Borough Council Road
R11 502112 245310 The Elms, Woburn Road Residential Bedford Borough Council
R12 505145 246795 Wilstead Road Residential Bedford Borough Council
R13 505149 246903 Wilstead Road Residential Bedford Borough Council
R14 505611 245117 Pheasant Grove Residential Bedford Borough Council
R15 505300 245576 Wixams Retirement Village Residential Bedford Borough Council
R16 506083 247284 Croyland Drive Residential Bedford Borough Council
Planning Inspectorate Scheme Ref: TR010044 4 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
R17 506779 247588 Bluebell Close Residential Bedford Borough Council
R18 508576 249526 Meadow Lane Residential Bedford Borough Council
R19 509289 251362 Embla Close Residential Bedford Borough Council
R20 509087 251191 St Neots Road Residential Bedford Borough Council
R21 507860 250661 Goldington Road Residential Bedford Borough Council
R22 507269 250494 Goldington Road Residential Bedford Borough Council
R23 506652 250251 Goldington Road Residential Bedford Borough Council
South Cambridgeshire R24 551577 259817 Dengaynes Farm, Newmarket Road Residential District Council
South Cambridgeshire R25 551019 259545 Newmarket Road Residential District Council
South Cambridgeshire R26 548543 261388 Fen Ditton, A14 Residential District Council
South Cambridgeshire R27 548163 261469 Northern Bridge Farm, Fen Road Residential District Council
R28 547295 261912 Cowley Road Residential Cambridge City Council
South Cambridgeshire R29 545801 262074 Mere Way Residential District Council
R30 545381 261904 Flack End Residential Cambridge City Council
South Cambridgeshire R31 544283 261866 Cambridge Road Residential District Council
South Cambridgeshire R32 544236 261793 Cambridge Road Residential District Council
South Cambridgeshire R33 544240 261618 Woodhouse Farm Residential District Council
South Cambridgeshire R34 543782 261598 Woodhouse Farm Residential District Council
South Cambridgeshire R35 543650 261586 Woodhouse Farm Residential District Council
South Cambridgeshire R36 542500 261375 Girton Road, Girton Residential District Council
R37 510083 249240 Dog House, Bedford Road Residential Bedford Borough Council
Planning Inspectorate Scheme Ref: TR010044 5 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
R38 510424 249310 Willington Road Residential Bedford Borough Council
R39 510663 249372 Bedford Road Residential Bedford Borough Council
R40 511319 249610 Bedford Road Residential Bedford Borough Council
R41 511532 249685 Barford Road Residential Bedford Borough Council
R42 512029 249530 Sandy Road Residential Bedford Borough Council
R43 512800 249464 Willowhill Cottages, Bedford Road Residential Bedford Borough Council
Central Bedfordshire R44 513953 249225 Bedford Road Residential Council
Central Bedfordshire R45 514183 249191 Bedford Road Residential Council
Central Bedfordshire R46 516103 248983 Bridge Farm Residential Council
Central Bedfordshire R47 517143 249348 St Neots Road Residential Council
Central Bedfordshire R48 516897 249546 St Neots Road Residential Council
Central Bedfordshire R49 516825 249656 St Neots Road Residential Council
Central Bedfordshire R50 516793 249804 St Neots Road Residential Council
Central Bedfordshire R51 516295 251844 Tempsford Road Residential Council
Central Bedfordshire R52 516239 253624 Great N Road Residential Council
R53 515421 255728 Roxton Road Residential Bedford Borough Council
R54 515480 256154 Chawston Lane Residential Bedford Borough Council
Central Bedfordshire R55 518286 249119 Swaden, Everton Road Residential Council
Central Bedfordshire R56 518578 249267 Lordswood Lodge, Everton Road Residential Council
Central Bedfordshire R57 519928 250911 Sandy Road Residential Council
Planning Inspectorate Scheme Ref: TR010044 6 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
Central Bedfordshire R58 520169 251158 Sandy Road Residential Council
South Cambridgeshire R59 521099 251206 Everton Road Residential District Council
Central Bedfordshire R60 525764 247318 High Street, Wrestlingsworth Residential Council
Rhadegund Cottages, Huntingdon South Cambridgeshire R61 538754 263640 Residential Road District Council
Huntingdonshire District R62 522278 272915 Overwater Close Residential Council
Huntingdonshire District R63 521820 272349 Bliss Close Residential Council
Huntingdonshire District R64 520587 271367 Thrapston Road Residential Council
Huntingdonshire District R65 520235 271516 Thrapston Road Residential Council
Huntingdonshire District R66 518472 271841 Woodhatch Farm, A14 Residential Council
Huntingdonshire District R67 516231 272009 Malting Lane Residential Council
Huntingdonshire District R68 513318 272746 High Street Residential Council
Huntingdonshire District R69 512919 273013 Littlecoates Close Residential Council
Huntingdonshire District R70 514482 272266 Wayside, Easton Road Residential Council
Huntingdonshire District R71 522340 273022 Overwater Close Residential Council
Huntingdonshire District R72 522772 273102 Knipe Close Residential Council
Huntingdonshire District R73 524275 274308 Howell Drive Residential Council
Huntingdonshire District R74 524941 273875 Sapley Road Residential Council
Planning Inspectorate Scheme Ref: TR010044 7 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
Huntingdonshire District R75 525386 273543 Eagle Way Residential Council
Huntingdonshire District R76 525968 273049 Elizabeth Drive Residential Council
South Cambridgeshire R77 527300 261049 Broadview, St Ives Road Residential District Council
South Cambridgeshire R78 527341 261353 Hunters Chase, St Ives Road Residential District Council
Huntingdonshire District R79 522594 256644 St Neots Road Residential Council
Huntingdonshire District R80 522470 256743 St Neots Road Residential Council
Huntingdonshire District R81 522153 256988 New Barns, St Neots Road Residential Council
Huntingdonshire District R82 521023 257645 Lansbury Road, St Neots Road Residential Council
Huntingdonshire District R83 519519 257877 Potton Road Residential Council
Huntingdonshire District R84 519597 257693 Potton Road Residential Council
Huntingdonshire District R85 518957 258698 Potton Road Residential Council
Huntingdonshire District R86 516926 258443 Great N Road Residential Council
Huntingdonshire District R87 516985 259164 Kenilworth Close Residential Council
R88 515082 259454 Bushmead Road Residential Bedford Borough Council
Huntingdonshire District R89 518916 266302 North Lodge, Great N Road Residential Council
Huntingdonshire District R90 518811 265722 The Vicarage, Great N Road Residential Council
South Cambridgeshire R91 532997 259912 Anson Road, Upper Cambourne Residential District Council
South Cambridgeshire R92 533440 259754 Hudson Road, Upper Cambourne Residential District Council
Planning Inspectorate Scheme Ref: TR010044 8 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
South Cambridgeshire R93 531937 260150 Crowdene, Cambourne Residential District Council
South Cambridgeshire R94 532649 260181 28 St Neots Road Residential District Council
3 Farm Cottages, Caxton Common, South Cambridgeshire R95 531634 260413 Residential Cambourne District Council
South Cambridgeshire R96 530429 260647 Caxton Gibbet Residential District Council
South Cambridgeshire R97 529088 261744 Ermine St S, Papworth Everard Residential District Council
South Cambridgeshire R98 534616 259832 St Neots Road, Bourn Residential District Council
South Cambridgeshire R99 533442 259986 27 St Neots Road, Knapwell Residential District Council
South Cambridgeshire R100 531355 260619 Lawn Farm, Cambourne Residential District Council
South Cambridgeshire R101 532331 260103 Bluebell Drive, Cambourne Residential District Council
South Cambridgeshire R102 532405 260253 St Neots Road, Cambourne Residential District Council
Streatham Gardens, Papworth South Cambridgeshire R103 528799 262093 Residential Everard District Council
South Cambridgeshire R104 537523 259608 167 St Neots Road, Hardwick Residential District Council
South Cambridgeshire R105 538190 259508 1 St Neots Road Residential District Council
South Cambridgeshire R106 536284 259716 St Neots Road Residential District Council
South Cambridgeshire R107 535959 259668 St Neots Road Residential District Council
South Cambridgeshire R108 536783 259708 293 St Neots Road Residential District Council
South Cambridgeshire R109 536873 260133 Scotland Farm, Scotland Road Residential District Council
Planning Inspectorate Scheme Ref: TR010044 9 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
South Cambridgeshire R110 540094 260097 Trinity Cottages, Cambridge Road Residential District Council
Moor Barn Farm Cottages, South Cambridgeshire R111 541508 259460 Residential Madingley Road District Council
South Cambridgeshire R112 539871 260205 Granary Court, Cambridge Road Residential District Council
South Cambridgeshire R113 540472 259451 Coton Court, Madingley Road Residential District Council
South Cambridgeshire R114 540768 259480 Mill Farm, Madingley Road Residential District Council
South Cambridgeshire R115 541703 259417 Bonde Mteko, Madingley Road Residential District Council
South Cambridgeshire R116 539807 262852 Hackers Fruit Farm, Dry Drayton Residential District Council
South Cambridgeshire R117 527102 247598 Tadlow Gate, Tadlow Road Residential District Council
South Cambridgeshire R118 528095 247490 Lower Road, Tadlow Residential District Council
South Cambridgeshire R119 531416 248429 45 Lower Road Residential District Council
South Cambridgeshire R120 530280 248182 Croydon House Farm, Lower Road Residential District Council
South Cambridgeshire R121 529628 247891 Lower Road, Croydon Residential District Council
South Cambridgeshire R122 528653 247629 The Spinney, Lower Road Residential District Council
South Cambridgeshire R123 531666 248569 Old Farm, Lower Road Residential District Council
South Cambridgeshire R124 533203 248815 Bridge House, Ermine Way Residential District Council
South Cambridgeshire R125 527730 247567 The Chestnuts, Tadlow Road Residential District Council
South Cambridgeshire R126 533991 249291 90 Cambridge Road, Wimpole Residential District Council
Planning Inspectorate Scheme Ref: TR010044 10 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
South Cambridgeshire R127 535235 250194 Cambridge Road, outside Wimpole Residential District Council
South Cambridgeshire R128 536124 250857 23 Hillside, Orwell Residential District Council
South Cambridgeshire R129 534797 249872 47 Cambridge Road, Wimpole Residential District Council
8 Cambridge Road, outside South Cambridgeshire R130 535214 250212 Residential Wimpole District Council
South Cambridgeshire R131 535913 250599 48 Fishers Lane, Orwell Residential District Council
South Cambridgeshire R132 530403 258211 29 Ermine Street, Caxton Residential District Council
Huntingdonshire District R133 527240 256125 2 Winchfield Great Gransden Residential Council
South Cambridgeshire R134 527016 255693 2 Church Street, Great Gransden Residential District Council
South Cambridgeshire R135 530421 258118 1 Ermine Street, Caxton Residential District Council
South Cambridgeshire R136 530018 257718 Gransden Road, Caxton Residential District Council
Huntingdonshire District R137 527280 256130 Audley Close, Great Gransden Residential Council
Huntingdonshire District R138 527626 256427 Claypit Cottages, Caxton Road Residential Council
Huntingdonshire District R139 527944 256494 Sand Road, Great Gransden Residential Council
Huntingdonshire District R140 527919 256518 Dunton Poultry Farm, Caxton Road Residential Council
Huntingdonshire District R141 528968 256897 Hardwicke Villa, Caxton Road Residential Council
Huntingdonshire District R142 529871 257755 Gransden Road, Caxton Residential Council
South Cambridgeshire R143 527062 255848 23 Middle Street, Great Gransden Residential District Council
Planning Inspectorate Scheme Ref: TR010044 11 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
South Cambridgeshire R144 527044 255750 6 Middle Street, Great Gransden Residential District Council
South Cambridgeshire R145 527120 255934 2 Caxton Road, Great Gransden Residential District Council
Central Bedfordshire R146 520762 248929 Snow Hill, Sandy Road Residential Council
Central Bedfordshire R147 521769 249203 27 Sandy Road, Potton Residential Council
Central Bedfordshire R148 522125 249115 Station Road, Potton Residential Council
Central Bedfordshire R149 522163 249097 21 Blackbird Street, Potton Residential Council
Central Bedfordshire R150 522273 249104 20 Sun Street, Potton Residential Council
Central Bedfordshire R151 521351 249185 94 Sandy Road, Potton Residential Council
Central Bedfordshire R152 522053 249171 26 Station Road, Potton Residential Council
Central Bedfordshire R153 522160 249116 2 Blackbird Street, Potton Residential Council
Central Bedfordshire R154 522268 249078 31 Sun Street, Potton Residential Council
Huntingdonshire District R155 526384 262433 181 High Street, Yelling Residential Council
Huntingdonshire District R156 526062 262573 127 High Street, Yelling Residential Council
Huntingdonshire District R157 525869 262747 Bridle End, Yelling Residential Council
Huntingdonshire District R158 525442 262614 28 High Street, Yelling Residential Council
Huntingdonshire District R159 525103 262650 Ingles Farm, High Street, Yelling Residential Council
Huntingdonshire District R160 524328 262529 5 High Street, Toseland Residential Council
Planning Inspectorate Scheme Ref: TR010044 12 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
Huntingdonshire District R161 522159 262549 Lodge Farm, Toseland Residential Council
Huntingdonshire District R162 520593 262845 Paxton Hill, Great Paxton Residential Council
Huntingdonshire District R163 520461 262563 Paxton Hill, St Neots Residential Council
South Cambridgeshire R164 525631 259871 School House, Cambridge Road Residential District Council
South Cambridgeshire R165 526728 259776 St Neots Road, Eltisley Residential District Council
South Cambridgeshire R166 524463 260064 Abbotsley Road, Croxton Residential District Council
Huntingdonshire District R167 523214 259980 Cambridge Road, Weald Residential Council
Huntingdonshire District R168 521904 259911 Cambridge Road, Wintringham Residential Council
Huntingdonshire District R169 521715 259985 Cambridge Road, Wintringham Residential Council
Huntingdonshire District R170 520978 260039 Greyholme, Cambridge Road Residential Council
Huntingdonshire District R171 520279 260295 Stone Hill, St Neots Residential Council
Huntingdonshire District R172 520058 260284 Loves Way, St Neots Residential Council
Huntingdonshire District R173 526324 262430 166 High Street, Yelling Residential Council
South Cambridgeshire R174 524913 259997 High Street, Croxton Residential District Council
Huntingdonshire District R175 525778 262718 87 High Street, Yelling Residential Council
Huntingdonshire District R176 524100 262533 High Street, Toseland Residential Council
Huntingdonshire District R177 520143 262328 135 Huntingdon Road, St Neots Residential Council
Planning Inspectorate Scheme Ref: TR010044 13 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
Huntingdonshire District R178 519904 260295 Lucas Crescent, St Neots Residential Council
Huntingdonshire District R179 521865 259878 Wintringham Residential Council
South Cambridgeshire R180 527230 259793 11 The Green, Eltisley Residential District Council
South Cambridgeshire R181 527269 259865 St Thomas, Eltisley Residential District Council
South Cambridgeshire R182 527065 259764 The Green, Eltisley Residential District Council
Huntingdonshire District R183 518991 267356 Great N Road, Buckden Residential Council
Huntingdonshire District R184 517112 260914 Wistow Court, St Neots Residential Council
Huntingdonshire District R185 517352 261263 Great N Road, St Neots Residential Council
Huntingdonshire District R186 517568 261726 Great N Road, St Neots Residential Council
R187 516809 260420 Duloe Road, St Neots Residential Bedford Borough Council
Huntingdonshire District R188 519108 261521 Hatley Close, St Neots Residential Council
South Cambridgeshire R189 542340 261456 Weavers Field, Girton Residential District Council
South Cambridgeshire R190 542241 261264 The Grange, Girton Residential District Council
South Cambridgeshire R191 541879 259288 Rectory Farm, Madingley Road Residential District Council
South Cambridgeshire R192 539369 259785 Church Lane, Madingley Residential District Council
South Cambridgeshire R193 539501 259415 Brierley House, Madingley Road Residential District Council
Anchor - Nelson Lodge Care Home, Huntingdonshire District R194 516444 258704 Residential Eaton Socon Council
Huntingdonshire District R195 516370 258895 14 Anson Place, Eaton Socon Residential Council
Planning Inspectorate Scheme Ref: TR010044 14 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
Huntingdonshire District R196 516373 259511 Duchess Close, Eaton Socon Residential Council
R197 516455 257129 Great N Road, Wyboston Residential Bedford Borough Council
R198 516411 256581 31 Great N Road, Wyboston Residential Bedford Borough Council
R199 516381 256580 35 Great N Road, Wyboston Residential Bedford Borough Council
R200 516336 256259 Nagshead Lane, Wyboston Residential Bedford Borough Council
R201 516383 256240 Great N Road, Wyboston Residential Bedford Borough Council
R202 516174 255814 25 Great N Road, Wyboston Residential Bedford Borough Council
R203 516468 256928 68 Great N Road, Wyboston Residential Bedford Borough Council
Huntingdonshire District R204 518581 258254 Lindisfarne Close, Eynesbury Residential Council
R205 518054 256884 Little Barford Residential Bedford Borough Council
R206 518057 256906 Little Barford Residential Bedford Borough Council
Huntingdonshire District R207 518683 258260 Lindesfarne Close, Eynesbury Residential Council
R208 515977 255070 Greenacres, Great N Road Residential Bedford Borough Council
Central Bedfordshire R209 517187 255718 The Barns, Tempsford Residential Council
R210 515898 256149 Chawston Lane, Wyboston Residential Bedford Borough Council
R211 514976 254719 Bedford Road, Roxton Residential Bedford Borough Council
Central Bedfordshire R212 516146 254597 Kelpie Marine Boat Yard Residential Council
Central Bedfordshire R213 516404 253895 15 Station Road, Tempsford Residential Council
Central Bedfordshire R214 516234 254038 Ferry Cottage, Great N Road Residential Council
Central Bedfordshire R215 516256 252624 Church Street, Church End Residential Council
Central Bedfordshire R216 516280 252063 Tempsford Road, Sandy Residential Council
Planning Inspectorate Scheme Ref: TR010044 15 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
Central Bedfordshire R217 516348 250793 21 Tempsford Road, Sandy Residential Council
Central Bedfordshire R218 516449 250717 24 Goldfinch Drive, Sandy Residential Council
Central Bedfordshire R219 516414 250503 Georgetown, Sandy Residential Council
Central Bedfordshire R220 516550 250281 1 Cottage Road, Sandy Residential Council
Central Bedfordshire R221 516536 249982 London Road, Sandy Residential Council
Central Bedfordshire R222 516534 249977 London Road, Sandy Residential Council
Central Bedfordshire R223 516490 250540 17 Crow Hill, Sandy Residential Council
Central Bedfordshire R224 516573 250160 140 London Road, Sandy Residential Council
Central Bedfordshire R225 516366 251591 Hillcrest, Tempsford Road Residential Council
Central Bedfordshire R226 517325 247953 62 High Road, Beeston Residential Council
Central Bedfordshire R227 518069 246456 5 A1, Lower Caldecote Residential Council
Central Bedfordshire R228 518161 246068 5 Great N Road, Lower Caldecote Residential Council
Central Bedfordshire R229 517707 248890 High St Roundabout, Sandy Residential Council
Central Bedfordshire R230 517937 248765 1 Potton Road, Sandy Residential Council
Central Bedfordshire R231 517555 247614 High Road, Seddington Residential Council
Central Bedfordshire R232 517595 247588 High Road, Seddington Residential Council
R233 510420 251396 Water End Roundabout Residential Bedford Borough Council
Central Bedfordshire R234 525994 246859 Eyeworth Road Residential Council
Planning Inspectorate Scheme Ref: TR010044 16 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
R235 507073 247775 Duchess Road, Eastcotts Residential Bedford Borough Council
Paxton Hall Care Home for the Huntingdonshire District R236 518605 263014 Residential Elderly Council
Huntingdonshire District R237 518531 262922 Manor Close, Little Paxton Residential Council
South Cambridgeshire R238 536112 259669 Gracefield Nursing Home Residential District Council
R239 517614 256249 Glebe Farm, Little Barford Residential Bedford Borough Council
Huntingdonshire District R240 519831 257469 Parkers Farm, Potton Road Residential Council
Huntingdonshire District R241 523398 260046 Cambridge Road, Wealden Residential Council
South Cambridgeshire R242 524491 260086 Cambridge Road, Croxton Residential District Council
R243 507980 250769 Bury Walk, Goldington Residential Bedford Borough Council
R244 510363 251752 Water End, Renhold Residential Bedford Borough Council
Huntingdonshire District R245 525859 267840 Depden Farm, Godmanchester Residential Council
Huntingdonshire District R246 530361 267379 Oxholme Farm, Hilton Road Residential Council
Huntingdonshire District R247 520207 268913 Orchard View, Brampton Road Residential Council
R248 506874 250336 334 Goldington Road Residential Bedford Borough Council
Central Bedfordshire R249 516454 249170 London Road Residential Council
Central Bedfordshire R250 516587 249081 Yew Tree Cottage Bedford Road Residential Council
Central Bedfordshire R251 516690 249094 Allison House Bupa (Care Home) Residential Council
Central Bedfordshire R252 518453 248598 Potton Road Residential Council
Central Bedfordshire R253 523220 248854 Wrestlingworth Road Residential Council
Planning Inspectorate Scheme Ref: TR010044 17 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
Central Bedfordshire R254 522941 249012 Bury Hill Residential Council
Central Bedfordshire R255 525609 247563 6 Potton Road Residential Council
Central Bedfordshire R256 526063 246923 1 Tadlow Road Residential Council
Huntingdonshire District R257 519046 267538 Ivelbury Close Residential Council
Huntingdonshire District R258 519113 267980 Taylors Lane, Buckden Residential Council
Central Bedfordshire R259 516604 249016 Rivermead Gardens, Sandy Residential Council
Huntingdonshire District R260 518504 262987 The Birches, Little Paxton Residential Council
Huntingdonshire District R261 518489 262689 109 High Street, Little Paxton Residential Council
Huntingdonshire District R262 523088 259933 Eltisley Manor (Care Home) Residential Council
R263 516651 257930 The Marbook Centre (Care Home) Residential Bedford Borough Council
Huntingdonshire District R264 516533 258680 Nelson Lodge (Care Home) Residential Council
Huntingdonshire District R265 518189 258195 Fern Court Residential Council
R266 515262 254592 33 High Street, Roxton Residential Bedford Borough Council
R267 515518 254610 37 School Lane, Roxton Residential Bedford Borough Council
Central Bedfordshire R268 517240 248166 High Road, Beeston Residential Council
Huntingdonshire District R269 518601 261805 Skipper Way, Little Paxton Residential Council
Lion House (& Grounds), South Cambridgeshire R270 527310 259903 Residential Cambridge Road, Eltisley District Council
House and Grounds, High Street, Huntingdonshire District R271 523671 262594 Residential Toseland Council
Planning Inspectorate Scheme Ref: TR010044 18 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
Central Bedfordshire R272 516533 249973 London Road, Sandy Residential Council
Central Bedfordshire R273 516532 249969 London Road, Sandy Residential Council
Central Bedfordshire R274 516530 249964 London Road, Sandy Residential Council
South Cambridgeshire R275 538352 263723 Foxhollow Residential District Council
Huntingdonshire District R276 518592 263687 Zaria, Great N Road Residential Council
R277 506662 250251 Goldington Road Residential Bedford Borough Council
R278 506636 250219 Newnham Avenue Residential Bedford Borough Council
Central Bedfordshire R279* 516577 249077 Bedford Road, Sandy Residential Council
Central Bedfordshire R280 516611 249103 Bedford Road, Sandy Residential Council
Central Bedfordshire R281 516578 249072 Bedford Road, Sandy Residential Council
Central Bedfordshire R282 516574 249061 Bedford Road, Sandy Residential Council
R283 506657 250250 Goldington Road Residential Bedford Borough Council
Central Bedfordshire R284 516540 249991 London Road, Sandy Residential Council
Central Bedfordshire R285 516504 249989 London Road, Sandy Residential Council
Central Bedfordshire R286 516544 250003 London Road, Sandy Residential Council
Central Bedfordshire R287 516524 250019 London Road, Sandy Residential Council
Central Bedfordshire R288 516554 250015 London Road, Sandy Residential Council
Central Bedfordshire R289 516556 250007 London Road, Sandy Residential Council
Planning Inspectorate Scheme Ref: TR010044 19 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
Central Bedfordshire R290 516550 250029 London Road, Sandy Residential Council
Central Bedfordshire R291 516552 250034 London Road, Sandy Residential Council
Central Bedfordshire R292 516559 250058 London Road, Sandy Residential Council
Central Bedfordshire R293 516564 250080 London Road, Sandy Residential Council
Central Bedfordshire R294 516566 250093 London Road, Sandy Residential Council
Central Bedfordshire R295 516578 250125 London Road, Sandy Residential Council
Central Bedfordshire R296 516578 250144 London Road, Sandy Residential Council
Central Bedfordshire R297 516560 249989 Carter Street, Sandy Residential Council
Redshank House, Cambridgeshire Huntingdonshire District H1 522123 272735 Healthcare & Peterborough NHS Council
Huntingdonshire District H2 522648 256425 Brookdale Healthcare Centre Healthcare Council
H3 506898 250345 Chrysalis Dental, Bedford Healthcare Bedford Borough Council
Central Bedfordshire H4 517188 249141 Kings Road Surgery, Sandy Healthcare Council
Central Bedfordshire H5 517332 249329 Sandy Health Centre Healthcare Council
Central Bedfordshire H6 517216 249274 Cloves Dental Practice, Sandy Healthcare Council
Central Bedfordshire H7 517298 249277 Sandy Dental Care Healthcare Council
Huntingdonshire District H8 517036 259175 Burnside Dental Clinic, Eaton Socon Healthcare Council
Central Bedfordshire H9 522526 249192 Brook End Surgery, Potton Healthcare Council
Cambridge Private Hospital, South Cambridgeshire H10 534858 249845 Healthcare Wimpole District Council
Planning Inspectorate Scheme Ref: TR010044 20 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
Buckden Surgery, Mayfield, Huntingdonshire District H11 519217 267333 Healthcare Buckden Council
Girton Branch Surgery, Pepys Way, South Cambridgeshire H12 542514 261606 Healthcare Girton District Council
S1 505676 244743 Lakeview School Education Bedford Borough Council
Barnabas Oley C of E Primary Huntingdonshire District S2 527040 255858 Education School Council
Bushmead Primary School Eaton Huntingdonshire District S3 516410 259234 Education Socon Council
S4 507583 250519 Goldington Green Academy Education Bedford Borough Council
S5 507634 250476 Goldington Green Lower School Education Bedford Borough Council
Orchard Park Community Primary South Cambridgeshire S6 544567 261642 Education School District Council
Central Bedfordshire S7 520478 251042 Everton Heath Primary School Education Council
Central Bedfordshire S8 525843 247329 Wrestlingworth VC Lower School Education Council
Huntingdonshire District S9 517072 257985 Treetops Nursery School Education Council
Huntingdonshire District S10 516921 258722 Orchards Day Nursery Education Council
Greenfields Day Nursery, Caxton Huntingdonshire District S11 527636 256400 Education Road Council
Central Bedfordshire S12 517486 249047 St Swithuns VC Primary School Education Council
S13 515396 254556 Roxton CE Academy Education Bedford Borough Council
Central Bedfordshire S14 521900 249407 Burgoyne Middle School, Potton Education Council
Just Learning Nursery, Huntingdonshire District S15 521995 272499 Education Hinchingbrooke Council
Wootton Community Nursery, S16 501558 244723 Education Bedford Borough Council Innovation Way
Dawn Until Dusk Preschool, S17 505619 244678 Education Bedford Borough Council Wixhams
Planning Inspectorate Scheme Ref: TR010044 21 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
ID X Y Location Class type Local authority
S18 506800 250321 University of Bedford Education Bedford Borough Council
Central Bedfordshire S19 517626 248944 Mini Explorers Day Nursery, Sandy Education Council
Schofield Centre, Madingley Road, S20 542162 259332 Education Cambridge City Council Cambridge
South Cambridgeshire S21 545922 261966 Cambridge Regional College, Milton Education District Council
South Cambridgeshire S22 545761 261795 Cambridge Regional College, Milton Education District Council
Huntingdonshire District P1 520398 259607 Wintringham Park 1 (Proposed) Proposed Council
Huntingdonshire District P2 520890 259966 Wintringham Park 2 (Proposed) Proposed Council
* Also modelled in the local air quality assessment for the construction of the Scheme.
Ecological sites
Planning Inspectorate Scheme Ref: TR010044 22 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Table 1-4 presents the transect locations within the designated ecological sites included in the air quality model. The locations of these receptors are shown in Figure 5.3 of the Environmental Statement [TR010044/APP/6.2].
Planning Inspectorate Scheme Ref: TR010044 23 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Table 1-4: Ecological receptors modelled in the local air quality assessment
Range of Critical X (of Y (of Name of distances Site name load (kg nearest nearest Local authority transect to edge of N/ha/yr) point) point) road (m)
E01 E01 was determined not to be nitrogen sensitive, thus was not modelled.
Central Lords Wood Ancient Woodland E02 3-200 10 518525 249264 Bedfordshire and County Wildlife Site (CWS)† Council
Central White Wood Ancient Woodland E03 3-200 10 521522 251613 Bedfordshire and CWS Council
South Gilrags Wood Ancient Woodland E04 183-200 10 529867 247829 Cambridgeshire and CWS District Council
Madingley Wood Site of Special South E05 126-200 Scientific Interest (SSSI) and 15 539808 259765 Cambridgeshire Ancient Woodland District Council
South Madingley Wood SSSI and E06 8-200 15 540052 259431 Cambridgeshire Ancient Woodland District Council
Huntingdonshire E07 2-200 St Neots Common SSSI 20 518661 261632 District Council
E08 E08 was determined not to be nitrogen sensitive, thus was not modelled.
Great Stukeley Railway Cutting Huntingdonshire E09 141-200 15 523502 273819 SSSI District Council
Great Stukeley Railway Cutting Huntingdonshire E10 1-200 15 523630 274356 SSSI District Council
South E11 45-200 Wilbraham Fens SSSI 15 551984 259698 Cambridgeshire District Council
East E12 9-90 Newmarket Heath SSSI 15 558827 261339 Cambridgeshire District Council
Bedford Borough E13 2-200 Little Barford CWS 20 517830 256599 Council
South E14 4-200 Croxton Park CWS 20 525305 259990 Cambridgeshire District Council
Planning Inspectorate Scheme Ref: TR010044 24 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Range of Critical X (of Y (of Name of distances Site name load (kg nearest nearest Local authority transect to edge of N/ha/yr) point) point) road (m) Central E15 0-200 Wyboston Pits CWS 20 517661 258060 Bedfordshire Council
Central E16 0-170 Wyboston Pits CWS 20 517661 258071 Bedfordshire Council
Huntingdonshire E17 37 Veteran Elm Tree 10 520340 258805 District Council
Central E18 23-50 Lords Wood Ancient Woodland 10 518955 249388 Bedfordshire Council
E19 E19 was determined not to be nitrogen sensitive, thus was not modelled.
E20 E20 was determined not to be nitrogen sensitive, thus was not modelled.
Great Stukeley Railway Cutting Huntingdonshire E21 0-200 15 523630 274365 SSSI District Council
South Elsworth A428 To Common E22 61-200 20 530504 260793 Cambridgeshire Farm CWS District Council
Bedford Borough E23 69-200 Elstow Pit CWS 20 504940 245957 Council
Central E24 6-200 Bunkers Hill CWS 10 520193 248713 Bedfordshire Council
Central E25 193-200 Carthagena Bridleway CWS 10 520914 248766 Bedfordshire Council
Bedford Borough E26 9-160 Cople Pits CWS† 15 509970 249190 Council
Bedford Borough E27 11-180 Cople Pits CWS† 15 510243 249253 Council
Bedford Borough E28 74-200 Cople Pits CWS† 15 509984 249293 Council
Central E29 43-70 Sandy Disused Railway CWS 10 520727 248864 Bedfordshire Council
Planning Inspectorate Scheme Ref: TR010044 25 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Range of Critical X (of Y (of Name of distances Site name load (kg nearest nearest Local authority transect to edge of N/ha/yr) point) point) road (m)
Central E30 72-200 Stewartby Lake CWS 15 500243 242668 Bedfordshire Council
East Beacon Course Green Lane E31 35-40 15 559246 262047 Cambridgeshire CWS District Council
Huntingdonshire E32 0-200 Buckden Gravel Pits CWS 10 521411 268357 District Council
Huntingdonshire E33 0-200 Buckden Gravel Pits CWS 10 521413 268383 District Council
Ellington Brook Pollard Willows Huntingdonshire E34 20-200 10 512366 273274 CWS District Council
East Heath Road / Street Way Green E35 196-200 20 557985 260000 Cambridgeshire Lanes CWS District Council
Hinchingbrooke Gravel Pits Huntingdonshire E36 2-200 15 521202 271752 CWS District Council
South Low Fen Drove Way Grasslands E37 7-200 15 549597 260307 Cambridgeshire and Hedges CWS District Council
South E38 0-30 Orwell Hill Roadside Verge CWS 20 536606 251189 Cambridgeshire District Council
South E39 0-10 Orwell Hill Roadside Verge CWS 20 536600 251195 Cambridgeshire District Council
Willow Pollards North of Wyton Huntingdonshire E40 90-200 10 526151 273123 Pit CWS District Council
South King's Hedges Hedgerow City E41 99-200 10 545538 261858 Cambridgeshire Wildlife Site (CiWS) District Council
Cambridge City E42 9-200 Milton Road Hedgerows CiWS 10 547309 261982 Council
Cambridge City E43 4-200 Scrub East of M11 Verge CiWS 10 542156 259346 Council
Planning Inspectorate Scheme Ref: TR010044 26 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Range of Critical X (of Y (of Name of distances Site name load (kg nearest nearest Local authority transect to edge of N/ha/yr) point) point) road (m)
South Madingley Slip Road Roadside E44 0 15 538504 259562 Cambridgeshire Verge CWS District Council
South Madingley Slip Road Roadside E45 0 15 539149 259694 Cambridgeshire Verge CWS District Council
South Madingley Slip Road Roadside E46 0-10 15 539145 259687 Cambridgeshire Verge CWS District Council
Track Southwest of Catworth Huntingdonshire E47 45-200 20 510640 273869 Gorse CWS District Council
Castle Farm Dairy Meadows Bedford Borough E48 3-200 20 509330 251321 County Wildlife Site Council
Central Everton Churchyard County E49 131-200 20 520277 251285 Bedfordshire Wildlife Site Council
Central E50 173-200 Everton Hill County Wildlife Site 20 519933 251213 Bedfordshire Council
Central Sandy Cemetery County Wildlife E51 5-130 10 517957 248762 Bedfordshire Site† Council
Central The Pinnacle County Wildlife E52 91-200 10 517756 248989 Bedfordshire Site Council
Grassland at the Vicarage Huntingdonshire E53 12-200 20 518887 265613 County Wildlife Site District Council
South Knapwell Roadside Verge E54 105-200 20 533460 259984 Cambridgeshire County Wildlife Site District Council
Toseland Churchyard County Huntingdonshire E55 23-50 20 524004 262581 Wildlife Site† District Council
South Barton Orchard County Wildlife E56 5-30 10 541646 256158 Cambridgeshire Site* District Council
Planning Inspectorate Scheme Ref: TR010044 27 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Range of Critical X (of Y (of Name of distances Site name load (kg nearest nearest Local authority transect to edge of N/ha/yr) point) point) road (m)
South Barton Orchard County Wildlife E57 10-170 10 541520 255981 Cambridgeshire Site* District Council
* This site has only been included in the construction modelling for phases 3 and 4 of construction. It is not within the study area for the operational phase. †These sites, in addition to the operational phase modelling, have also been included in the construction modelling for phases 2, 3, and 4 of construction.
1.3 Model post processing General protocol The following post-processing procedures have been applied to the modelled road-contributed NOX concentrations at receptors:
a. Conversion of road-contributed NOX to total NO2 concentrations (with the addition of background concentrations). b. Application of adjustment factors derived from model verification to bring modelled concentrations into line with monitored concentrations.
c. Application of Highways England LTTE6 projection factors to the modelled DM and DS NO2 concentrations to account for the observed gap between projected vehicle emission reductions and the estimated annual rate of improvement in annual mean NO2.
In this study, modelled road contributed NOX concentrations have been converted to total NO2 concentrations using Defra’s NOX to NO2 calculator V7.1.1 (Ref 4). The year and local authority area for which the modelling has been undertaken are specified, along with the appropriate Defra background NO2 concentrations at each receptor. The calculation then applies an appropriate factor of NOX emitted as NO2.
The modelled road-contributed PM10 concentrations were adjusted using the factors derived from the NO2 verification procedure, and then background concentrations of PM10 were added to obtain total PM10 concentrations.
The adjusted road-contributed PM10 concentrations were also taken to represent worst-case PM2.5 concentrations (PM2.5 is a fraction of PM10), and then background concentrations of PM2.5 were added to obtain total PM2.5 concentrations.
Planning Inspectorate Scheme Ref: TR010044 28 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Background concentrations To obtain predictions for total pollutant concentrations at receptors, the model outputs of road contributions of NOX and PM10 must be combined with background concentrations. Background concentrations are those from many sources which individually may not be significant, but collectively, over a large area, need to be considered. Annual average background concentrations have been derived from Defra’s most recent 1x1 kilometre background maps (Ref 5). The earliest background map available in the current dataset is 2017. To back-cast this to 2015 for NOX and NO2, monitored NOX data for 2015 and 2017 for four local background monitoring sites was compared, and an average factor of 0.98 was found to translate 2017 data to represent 2015. In accordance with LAQM.TG(16) (Ref 6), as modelled national background maps are used in the assessment, these were first compared to local background monitoring to check they were representative of the area. Where the comparison showed that concentrations modelled in the national background maps did not agree with local background monitoring, adjustment of the background map concentrations was undertaken. The ‘total concentrations’ modelled in the national background maps also include local sources which are not considered to represent background values. Therefore, before adjustment, sector removal of emissions from motorways, trunk roads and A roads was undertaken using Defra’s Sector Removal tool (Ref 7). This was to ensure the modelled national background maps were being compared with local background monitoring data on a like-for-like basis.
Before adjustment, the modelled NO2 national background mapped values underestimated the monitored NO2 at 4 local background monitoring locations by an average of 23%. The root mean square error (RMSE) of the unadjusted data 3 was 4.0µg/m . An adjustment factor of 1.32, to be applied to the NOX national background map, was derived using linear regression. After application of the 3 adjustment factor and reconversion to NO2, the RMSE was reduced to 1.3µg/m . The adjusted sector-removed modelled national background maps were then used as inputs to follow on calculations in the assessment process for all scenarios. Sector removal of motorways, trunk roads and A roads is appropriate, as these roads will be directly modelled.
For PM10, monitoring sites across the wider national Automatic Urban Rural Network (AURN) network were used to back-cast 2017 background maps to 2015, due to the absence of suitable local monitoring data. Two sites were compared, and an average factor of 1.13 was found to translate 2017 data to represent 2015.
Planning Inspectorate Scheme Ref: TR010044 29 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Verification Model verification was undertaken using monitoring sites within the study area. Background sites were not used in verification and are not considered further. From these sites, only those representative of modelled sensitive receptor locations and with sufficient data capture were considered suitable for the purposes of model verification. Following detailed analysis of each monitoring location a total of 14 monitoring sites were taken forward in the model verification process. Table 1-5 details the sites removed from the verification process, whilst Table 1-6 details the sites used in verification. Table 1-5: Monitoring sites excluded from model verification
Site ID Local authority X, Y Reason for exclusion from verification
Bedford Borough 506626, DT57 Behind a sign Council 250226
Bedford Borough 506633, DT59 Too close to kerbside Council 250206
Bedford Borough 506542, DT61 Too close to kerbside and just above a sign Council 250296
Central 516485, N1 Bedfordshire In a hedge 249202 Council
Central 516569, N17 Bedfordshire In a hedge 249074 Council
Central Exact location could not be verified in streetview images, 516579, N18 Bedfordshire and inconsistent results compared to other similar 249070 Council locations were predicted
Central Exact location could not be verified in streetview images, 516524, N19 Bedfordshire and inconsistent results compared to other similar 249139 Council locations were predicted
Central 516551, N28 Bedfordshire No traffic data for Carter Rd 249967 Council
South 543739, IMP Cambridgeshire Roadworks in 2015 on A14; not suitable 261625 District Council
South Exact location could not be verified in streetview images, 538744, DT5 Cambridgeshire and inconsistent results compared to other similar 263640 District Council locations were predicted
Planning Inspectorate Scheme Ref: TR010044 30 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Site ID Local authority X, Y Reason for exclusion from verification
South 528131, DT7 Cambridgeshire No traffic data for High St 247399 District Council
South 544119, DT12 Cambridgeshire No traffic data for Lone Tree Avenue 261862 District Council
South Exact location could not be verified in streetview images, 540509, DT18 Cambridgeshire and inconsistent results compared to other similar 262290 District Council locations were predicted
South 544828, DT20 Cambridgeshire No traffic data for Chieftan Way 261738 District Council
South 545056, DT21 Cambridgeshire No traffic data for Neal Drive 261784 District Council
South 545435, DT22 Cambridgeshire No traffic data for Topper Street and Busway NCN51 261906 District Council
South 545169, DT26 Cambridgeshire No traffic data for Topper Street 261764 District Council
Huntingdonshire 516370, EatonSocon Suburban site not suitable for verification District Council 259514
Huntingdonshire 519197, Buckden No traffic data for the lane it's on District Council 267955
Huntingdonshire 519756, Brampton3 Suburban site not suitable for verification District Council 269900
Huntingdonshire 522293, Huntingdon4 No traffic data for Blethen Drive District Council 272909
Huntingdonshire 519956, Brampton5 Suburban site not suitable for verification; data capture low District Council 271461
Planning Inspectorate Scheme Ref: TR010044 31 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Table 1-6: Monitoring sites used in model verification
Site ID Model ID Site location X Y Local authority
Bedford Borough DT21 LA1 Gt North Road, (A1) North 516379 256411 Council
Bedford Borough DT29 LA2 Goldington Road/ Opposite Uni 506623 250273 Council
Bedford Borough DT12 LA17 The Lane, Wyboston 516351 256589 Council
Central Bedfordshire N6 LA6 Bedford Rd Sandy 516619 249100 Council
Central Bedfordshire N20 LA7 A1 Carter Lane Sandy 516533 249974 Council
Central Bedfordshire N16 LA8 Bedford Rd Sandy 516593 249084 Council
Central Bedfordshire N25 LA10 The Akbar A1 Sandy 516570 250175 Council
Huntingdonshire District Buckden2 LA19 4 High Street (roundabout) 519075 267424 Council
Huntingdonshire District Buckden3 LA20 34 High Street (shop) 519166 267625 Council
Huntingdonshire District Buckden4 LA11 11 Taylors Lane 518979 267370 Council
South Cambridgeshire DT3 LA18 Hill Farm Cottages, Lolworth 536927 264957 District Council
South Cambridgeshire DT16 LA14 Hackers Fruit Farm, Lolworth 539865 262816 District Council
South Cambridgeshire DT19 LA16 Crafts Way, Bar Hill 538473 263676 District Council
Huntingdonshire District Brampton 1 LA12 1 Laws Crescent 520161 271557 Council
Planning Inspectorate Scheme Ref: TR010044 32 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Unadjusted modelled estimates of total annual mean NO2 concentrations have been compared against monitored annual means. Of the 14 sites considered in model verification, six had predicted NO2 concentrations within +/- 10% of monitored without adjustment as shown in Table 1-7. Six further sites had predicted NO2 concentrations within +/- 25%, and the remaining 2 sites substantially underestimated by more than 25%. The results of the unadjusted model verification have been used to define two model domains, which are listed below. A specific location experiencing unique dispersion characteristics accounting for the substantial underestimate has been designated the ‘A1 Houses’ zone, whereas all other monitors considered in verification make up the ‘General’ Zone. Uncertainty in modelled estimates has been assessed by calculating RMSE. The RMSE values obtained for unadjusted modelled estimates of NO2 compared to monitored concentrations are shown in Table 1-7, split by model domain. The RMSE target value according to Defra’s Local Air Quality Management Technical Guidance (LAQM.TG(16)) (Ref 6) for the 40µg/m3 objective concentration for 3 annual mean NO2, is less than 4µg/m (10% of the objective) and not greater than 25% of the objective i.e. 10µg/m3. Without adjustment it is shown that the RMSE is above the target value in the General domain. As noted previously, the A1 Houses domain has a substantial underestimate (although statistics do not apply), suggesting that model adjustment is required for all domains. A further comparison of modelled estimates of road contributed annual mean NOX with the road NOX component derived from monitoring data was undertaken using Defra’s NO2 to NOX calculator, version 7.1.1. The results of the comparison of modelled and monitored road NOX indicates that the model exhibits systematic bias both model domains. As such, in order to improve model performance, model adjustment factors were derived, in accordance with the methodology described in LAQM.TG16. The model adjustment factors applied to modelled road NOX contributions within each model domain are summarised below in Table 1-7. A comparison of the unadjusted and adjusted modelled estimates of total annual mean NO2 with monitored concentrations is presented in Table 1-8. The results show that the adjusted NO2 concentrations modelled at the 14 monitoring sites are within +/- 10% of monitored concentrations following model adjustment at 7 out of 13 sites within the ‘General’ model domain. The RMSE in the ‘General’ model domain is almost at the ideal value, as shown in Table 1-7.
Planning Inspectorate Scheme Ref: TR010044 33 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Table 1-7: Verification statistics
Number of Number of RMSE Fraction Number monitoring sites Model monitoring sites pre- Adjusted al Bias Model of site within ±10% of the adjust- within ±10% of adjust- model post domain comparis monitored ment the monitored ment RMSE adjust- ons concentration pre- factor concentration (µg/m3) ment) adjustment post adjustment
A1 Houses 1 0 - 4.48 - - 1
General 13 6 5.2 1.23 4.2 0.0 7
“-“ indicates where only one measurement location is within a model zone and therefore statistics cannot be calculated Table 1-8: Verification details at monitoring sites
Modelled Monitored road- Modelled road- Modelled total NO2 Monitored 3 total NO2 Site contributed NOX contributed NOX (µg/m ) pre- NO (µg/m3) (µg/m3) post- 2 (µg/m3) (µg/m3) adjustment adjustment Model domain A1 Houses
LA7 67.3 135.4 30.2 28.0 67.3
Model domain General
LA1 37.0 51.5 42.9 33.4 38.5
LA2 34.0 32.9 15.7 26.1 28.2
LA6 33.3 42.0 29.4 27.7 31.4
LA8 39.3 56.3 37.0 31.1 35.7
LA10 34.3 44.8 29.3 27.4 31.2
LA11 21.1 19.5 17.8 20.4 22.4
LA12 22.7 16.5 16.3 22.6 24.8
LA14 34.0 46.2 46.7 34.2 39.8
LA16 20.6 16.4 11.6 18.2 19.8
LA17 21.0 16.1 16.2 21.1 22.9
LA18 30.9 39.7 42.8 32.3 36.5
LA19 25.6 26.5 20.7 22.8 25.1
LA20 28.9 33.7 11.9 18.5 19.8
Planning Inspectorate Scheme Ref: TR010044 34 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Plates 1-2 and 1-3 illustrate the unadjusted, and adjusted model performance respectively.
Plate 1-2: Comparison of modelled NOX against monitored NOX in the ‘General’ zone prior to adjustment
Planning Inspectorate Scheme Ref: TR010044 35 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
Plate 1-3: Comparison of modelled NOX against monitored NOX in the ‘General’ zone post- adjustment
Planning Inspectorate Scheme Ref: TR010044 36 Application Document Ref: TR010044/APP/6.3
A428 Black Cat to Caxton Gibbet improvements Environmental Statement Appendix 5.3: Air quality assessment methodology
1.4 References Ref 1 Cambridge Environmental Research Consultants Ltd (2020) ADMS-Roads version 5.0
Ref 2 Highways England (2019). DMRB, LA 105 ‘Air quality’ Revision 0. https://www.standardsforhighways.co.uk/dmrb/search/10191621-07df-44a3- 892e-c1d5c7a28d90
Ref 3 ADM Ltd (2020). https://www.aboutair.com/
Ref 4 Department for Environment, Food and Rural Affairs (2019) NOX to NO2 Calculator v7.1.1
Ref 5 Department for Environment, Food and Rural Affairs (2019). 2017-based background maps for NOX, NO2, PM10 and PM2.5. https://uk-air.defra.gov.uk/data/laqm-background-maps?year=2017
Ref 6 Department for Environment, Food and Rural Affairs (2018). Local Air Quality Management Technical Guidance (TG16). https://laqm.defra.gov.uk/documents/LAQM-TG16-February-18-v1.pdf
Ref 7 Department for Environment, Food and Rural Affairs (2019). NO2 Adjustment for NOX Sector Removal Tool v7.0. https://laqm.defra.gov.uk/review-and-assessment/tools/background- maps.html#NOxsector
Planning Inspectorate Scheme Ref: TR010044 37 Application Document Ref: TR010044/APP/6.3