London Borough of Hillingdon

WRITTEN SUMMARY OF ORAL SUBMISSION AND INFORMATION REQUESTED NOVEMBER 2015 (ENVIRONMENT HEARING) – APPENDIX E – CUMULATIVE ASSESSMENTS AND LOCAL IMPACTS

HIGHWAYS ENGLAND'S RESPONSE

1.1 The following comments are in response to questions various questions (including 2, 8 and 23) of the Environment hearing specific topics (transport themes). The response to the questions have been grouped together to provide a definitive position on the cumulative assessment and local impacts which are inherently linked.

1.2 Additional information was supplied to the Council by the applicant and this has now been reviewed and considered in the Councils response.

Background

1.3 Prior to considering the cumulative and local impacts of the scheme, it is necessary to establish the context. The M4 provides the east/west access for the southern part of the London Borough of Hillingdon. It is therefore the primary route into and out of London. In addition, much of Hillingdon's business and industrial uses are located in the south of the Borough near Heathrow airport. The M4 and its links into the south of the borough are therefore extremely important and commensurately busy.

1.4 There are two junctions serving Hillingdon's local network, Junction 3 (connecting the A312) and Junction 4 (M4 Heathrow Spur and A408). The map below shows the M4 in the context of the South of the Borough.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 1 Highways England Figure 1; Reference Map

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 2 Highways England 1.5 In turn, Figure 2 below; air quality map, shows recent modelling information on the areas exceeding air quality limit values. The map shows significant problems on the supporting network to the M4 particularly around the A312 (although mapping is not available for that part of the road outside of the borough).

Figure 2; Air Quality

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 3 Highways England 1.6 It is essential that the impacts of the proposed development are fully understood to ensure a suitable approach to mitigation. Highways England acknowledges that the proposed scheme will result in a freer flowing motorway and therefore a more attractive transport option. They acknowledge that the proposed scheme will result in an increase in traffic on the motorway. It would therefore be expected that there would be an increase in traffic to and from each of the junctions along the route.

Highways England Comment 1.6.1 Highways England acknowledges that the M4 provides an important link to the local highway network within the London Borough of Hillingdon, providing access to Hillingdon’s business and industrial centres and facilitating future development within the Borough. Highways England agrees that the proposed Scheme will result in an increase in traffic on the motorway and to a lesser extent, an increase in traffic flows using junctions 3 and 4. Information on these traffic impacts has been provided to LBH in response to questions raised by email to Highways England. A copy of the information provided to LBH is at Attachment 2 to this Appendix E. This information demonstrates that the majority of the increase in traffic at junctions 3 and 4 is through traffic and not turning to/from the local road network at either junction.

Cumulative Assessment

1.7 The Council responded to initial requests in 2014 for the relevant information on what it considered reasonably foreseeable development to be included within the ES as part of a cumulative assessment. However, at the hearing it was established that the baseline for the transport assessment was 'frozen' in 2013 thus predating the request.

Highways England Comment 1.7.1 In response to a request from Highways England in December 2014 for information on developments to be included in the environmental cumulative assessment, LBH submitted a list (as provided at Appendix 2 to LBH’s comments on the Examining Authority’s first written questions) of some 25 sites that in their view should be considered as part of that assessment. Highways England has reviewed each of these sites, including those that have come forward after the freeze date for traffic modelling purposes of February 2014. A copy of the tabulated list, together with Highways England’s responses, is included appended to the end of this response document (Attachment 1 to this Appendix E). For each of the sites put forward by LBH for consideration, Highways England has reviewed the relevant planning application documentation, including the applicant’s transport assessments. In the majority of cases the applicant had demonstrated to the Council’s satisfaction that there was no net detriment to the local transport network arising from the development or that the additional trips associated with the development had already been accounted for within the NTEM growth allowed for in the M4 model. Accordingly, none of the sites other than the NATS site and Southall Gas Works in LB Ealing, has been identified as requiring individual assessment. These latter two sites have been explicitly assessed within the M4 traffic forecasts.

1.8 As a consequence the list of developments used in the transport assessment outlined in Appendix 16.2 is different from the more comprehensive list of developments outlined Appendix 16.1 that are indicated will be used in cumulative assessments.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 4 Highways England Highways England Comment 1.8.1 Chapter 16 of the ES (Examination reference APP-156) describes the approach undertaken to the assessment of combined and cumulative effects. As explained in paragraph 16.3.4, a list of development proposals was compiled, with the last update being in January 2015. It is acknowledged that LBH was one of the six authorities from the total of 11 ‘host’ authorities who provided input to this process. As further explained in paragraph 16.3.11, a study area defined as being within 1km of the M4 was adjudged to be appropriate to assess the cumulative environmental impacts. Accordingly Appendix 16.1 (Examination reference APP-356) lists those developments within the 1km band that were included in the cumulative environmental assessment. The traffic forecasts for the Scheme (on which the air quality and noise assessments were based) were developed from information on transport and development proposals collated up to February 2014. This assessment was not restricted to the 1km band and instead covered the wider traffic model study area. Consideration was given to the need to model those developments that met the criteria set out in paragraph 16.3.6 of the ES. Where the forecast growth allowance for population and/or employment for the particular model zone under consideration within NTEM was considered to adequately take account of the proposed development, the decision was taken that it was not necessary to explicitly model the development. Where there was a significant difference between the existing land use and that proposed with development and therefore where a growth factor approach would not fairly represent the impact of the development, the decision was taken to explicitly model the proposed development. Appendix 16.2 lists those developments included in the traffic model. Those developments in Appendix 16.2 that fall within the 1km band and therefore qualified for consideration in the separate environmental (excluding air quality and noise) cumulative assessment are highlighted in yellow in Appendix 16.2.

1.9 It is therefore clear that the transport assessment did not clearly consider the future developments determined to be reasonably foreseeable. However, at the hearing, Highways England indicated whilst some developments were specifically referred to in appendix 16.2, others not referenced were in any event accounted for in their forecasted growth scenarios.

Highways England Comment 1.9.1 As explained above in paragraph 1.8.1, Highways England undertook a comprehensive assessment of future developments. If the application of a growth factor based on NTEM to existing land use fairly represents the effects of future development in scale and location, it is not necessary to individually model it. That does not mean that individual development proposals are ignored; account is taken of them in the overall forecasts.

1.10 It remains unclear why Highways England identified some specific developments, but not others. Furthermore, it is not clear what assumptions have been made for the future growth, particularly in Hayes (linked to the A312 and then Junction 3) where significant strategic growth has been identified by the Council.

1.11 Figure 3 below; Cumulative development map, identifies the range of developments, some partially completed (with permission), some with permission but not commenced, some in the planning process (submitted but not yet approved) and others allocated for future growth.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 5 Highways England Figure 3; Cumulative development map

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 6 Highways England 1.12 The total of this development amounts to over 5000 new homes and hundreds of thousands of sqm of new commercial uses (including business and industrial). These will all add significant traffic to the local area, including in particular the A312 and Junctions 3 and 4 of the M4.

1.13 In addition, the Council is keen to understand the level of growth allowed for along the A4 (south of the M4) and in particular the amount of hotels and other growth in close proximity to Bath Road.

Highways England Comment Growth Assumptions

1.13.1 In response to the question relating to the growth assumptions within the M4 smart motorway model, the approach to developing forecasts from a validated base year is to apply growth factors to the base year trips. For Highways England (and most local authority models), the starting point is the National Trip End Model ("NTEM"). TAG Unit M4 (Forecasting and Uncertainty) paragraph 7.1.7 states: “NTEM represents the Department’s central assumption of growth in travel demand between any two given years. When modelling for business cases is submitted to the Department, scenarios assuming central growth in demand (such as the core scenario, described in section 3) must be controlled to the growth in travel demand in the NTEM dataset at an appropriate spatial area TAG Unit M4 Forecasting and Uncertainty (usually Local Authority / District level).”

1.13.2 The validated base year for the M4 smart motorway model is 2009. Forecasts were developed for the years 2022 and 2037, representing the Scheme opening and design years respectively. The NTEM growth factors were obtained from the Trip End Model Presentation Program ("TEMPRO") version 6.2. The respective planning data statistics within NTEM for the LB Hillingdon are tabulated below.

Population Households Jobs Workers 2009 246,652.6 101,940.6 225,273.2 112,541.4 2022 267,710.6 110,342.4 253,034.8 122,802.6 Increase (09-22) 21,058 8,401.8 27,761.6 10,261.2 Growth Factor 1.0853 1.0824 1.1232 1.0911

2037 286,509 116,791 271,045 128,245 Increase (09-37) 39,856.4 14,850.6 45,771.8 15,703.6 Growth Factor 1.1615 1.1456 1.2031 1.1395

Increase (22-37) 18,798.4 6,448.8 18,010.2 5,442.4 Growth Factor 1.0702 1.0584 1.0711 1.0443 Table 1: LB Hillingdon Demographic Planning Data (source: TEMPRO v6.2)

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 7 Highways England 1.13.3 The LBH draft Local Plan Part 2 – Site Allocations and Designations document sets out the Borough’s proposed land allocations in line with its forward growth plans. Table 2.1 of the above document presents a summary of growth in the Borough being planned within the Local Plan Part 1 between 2011 and 2026. The following two statistics are of note:

 Total new jobs: 9000 – 11000; and  Total new homes: 6375. 1.13.4 The comparative statistics within the National Trip End Model v6.2 for LB Hillingdon between 2009 (M4 smart motorway model base year) and 2022 (Scheme opening year) shown above in Table 1 are:

 Total new jobs: 27,762; and  Total new households: 8402. 1.13.5 Accordingly, it is concluded that the M4 smart motorway model makes adequate allowance for the planned level of growth across Hillingdon, going even further than the Council's own predictions for growth.

1.13.6 By way of further illustration, the corresponding NTEM trip end growth factors derived from the above planning data in Table 1 are tabulated below.

Trip End Growth Period Productions Attractions ( 2009 – 2022 1.1195 1.1731 Average weekday ( 2009 – 2037 1.224 1.3434 ( 2022 - 2037 1.0932 1.1451

( 2009 – 2022 1.1147 1.1563 AM Peak Hour ( 2009 – 2037 1.1987 1.293 ( 2022 - 2037 1.0753 1.1182 Table 2: LB Hillingdon Trip End Growth Factors (source: TEMPRO v6.2)

1.13.7 The comparative forecast growth in traffic using the M4 between junctions 3 and 4 for the do-minimum (without Scheme) scenario is tabulated below.

M4 Growth (J3-4) Period Eastbound Westbound ( 2009 – 2022 1.08 1.01 AM1 (07.00-08.00) ( 2009 – 2037 1.14 1.02 ( 2022 - 2037 1.05 1.01

( 2009 – 2022 1.11 1.04 AM2 (08.00-09.00) ( 2009 – 2037 1.13 1.05 ( 2022 - 2037 1.02 1.01

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 8 Highways England Table 3: Forecast Do-Minimum traffic growth on M4 J3-4 (factors calculated from Tables A-14 and A-15, Traffic Forecasting Report).

1.13.8 From a comparison of Tables 2 and 3, it can be seen that the growth forecast in the transport model for the M4 between junctions 3 and 4 in each of the two modelled AM peak hours is slightly below the overall district-level growth for Hillingdon for the equivalent time period. It is to be stressed that neither set of figures includes the M4 smart motorway, and both include the allowances for development-related growth incorporated in NTEM. This demonstrates that the M4 motorway is not driving the future increase in traffic flows through the Borough as trips within the Borough will grow at a faster rate than the motorway.

Treatment of Individual Developments

1.13.9 Transport Analysis Guidance Unit M4 – Forecasting and Uncertainty – describes the process to be followed where it is considered that uncertainty associated with planned developments can have a material effect on the forecasts that would not be captured by the district-wide use of NTEM. Paragraph 7.3.5 of the Unit states: “If land use developments are a source of uncertainty, the spatial distribution of trip ends at a detailed level will need to be adjusted in accordance with likely travel from the development, based on the evidence available. Over a wider spatial area, growth in demographic data must be constrained to the appropriate Department-based projections (NTEM in the core scenario).” The criteria for inclusion of development proposals for inclusion in the core scenario are provided in Table A2 of Unit M4, a copy of which is provided below:

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 9 Highways England

Uncertainty Log Classifications (Table A2 – Tag Unit M4: Forecasting and Uncertainty)

1.13.10 As can be seen from reference to Table A2, only developments categorised as ‘near certain’ or ‘more than likely’ should be included within the core scenario.

1.13.11 The key principle underlying the development of forecasts is that they be constrained to the NTEM totals at the District level. Therefore, where it is decided appropriate to represent individual development proposals of a significant scale within the traffic model, the trips associated with those developments need to be substituted for the equivalent number already contained within the District total. This allows the required control to be maintained in terms of aggregate total, but with certain trips properly represented within the geographical area in which they actually occur.

1.13.12 The TEMPRO software (described in paragraph 7.1.6 of the Unit) provides an alternative assumptions facility to adjust NTEM trip ends to exclude development sites (for which the trip ends will be calculated separately). This can be used as follows:

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 10 Highways England  calculate the number of households and/or jobs in the NTEM zone resulting from developments (dwellings are often taken as a proxy for households);  subtract the number of households and/or jobs thus calculated from the zone totals in NTEM;  enter these data into TEMPRO (alternative planning assumptions) and rerun, to calculate the growth in trip ends excluding the developments;  add the development trip ends based on the Transport Assessment; and  check and report the total trip ends. These should be very close to the NTEM total for the given NTEM zone. 1.13.13 This process was applied for the large-scale developments within Hillingdon at RAF Uxbridge and the former National Air Traffic Services ("NATS") sites, the development of each of which was considered to result in a significant change from their respective previous land uses. Therefore, individual trip generation and distribution assumptions were developed for each of these proposed developments, in effect following the process normally undertaken to produce Transport Assessments for development proposals. These bespoke site-specific trip generations were then allocated into the M4 model forecasts and the balance of growth adjusted at the district level in accordance with the TAG method.

1.13.14 For the remainder of the development sites considered to be of sufficient size to warrant individual consideration (>50 housing units or >1000m2 employment or commercial floorspace), reference was made to the respective planning documentation. Many of the sites proposed for development within the Hayes and Heathrow areas of Hillingdon in particular, comprise redevelopment of existing or vacant brownfield sites. If the review of the planning documentation suggested that the traffic associated with the sites would be allowed for within the overall NTEM growth allocated to the particular zone within the model, and the traffic from the development would be appropriately modelled in terms of its loading on to the highway network, then the decision was taken not to develop an individual assessment for such sites. It must be stressed that this does not mean such sites were ignored; instead a proportionate approach was taken to the development of the model forecasts on the basis that appropriate account was taken of the various developments within the overall forecasts. As explained in paragraph 5.1.2 of TAG Unit M4, “Appreciation of every possible permutation of sources of uncertainty would require a very large number of model runs that would take an unacceptable amount of time to run. Therefore it is important that analysis of alternative scenarios is proportionate as well as sufficiently comprehensive”.

1.13.15 The NTEM does not have a specific statistic for forecasting hotel bedrooms. Within the M4 smart motorway model, growth in Hillingdon is concentrated in those model zones within the urban areas and these zones typically exhibit growth rates between 2% and 4% per annum. It is considered that this level of growth makes adequate allowance for traffic associated with hotel developments, which are mainly concentrated in the model zones in the proximity of Heathrow Airport. In addition, it is noted that Table 2.1 of the LBH draft Local Plan Part 2 – Site Allocations and Designations document states that the projected number of additional hotel bedrooms planned between 2011 and 2026 is between 3800 and 5600. The total number of beds accounted for in the 8 hotel applications in the LBH Appendix 2 tabulation is 3450. This means that the majority of the planned increase in hotel beds is already accounted for in the applications included in LBH Appendix 2. From a review of these applications, none of these hotels has been identified as having a material impact on the local highway network. Accordingly, it is concluded that the current assessment based on the above growth rates takes adequate account of future hotel development.

1.14 For clarity, the Council does not consider it necessary to include a cumulative assessment with an additional runway for Heathrow as this does not yet fall within the scope of reasonably foreseeable.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 11 Highways England Highways England Comment 1.14.1 Highways England notes that LBH does not consider it necessary to include a cumulative assessment for an additional runway for Heathrow and concurs with that view as the matter currently remains under consideration by the Government.

Local Assessment

1.15 Given the above, the Council would have expected a more detailed analysis of the impacts on junctions 3 and 4 and the wider network supporting these sections of the motorway.

1.16 At the November hearing, Highways England advised that there was limited local assessment work undertaken. Outside of the hearing and not in the ES, Highways England has provided limited information on the impacts of the scheme on the junctions in Hillingdon.

1.17 This limited information only shows specific periods of the day and focuses on the traffic movements on Junction 3 and not the wider local network. An extract of the junction diagrams is included in Figure 3.

Highways England Comment 1.17.1 Highways England has provided additional analyses of traffic flows in response to specific questions raised by the LBH. The specific periods of the day referred to by the Borough are the modelled peak periods when any changes in traffic flow are likely to be most significant. The Borough has raised specific questions in respect of both junctions 3 and 4 and data has been made available on each. A meeting was convened with LBH on 21 December 2015 to review matters within the draft Statement of Common Ground. At the meeting LBH were briefed on the outcome of a review of each of the development sites raised by LBH in their submission of 7 December, together with the 25 sites included as Appendix 2 to LBH’s comments on the Examining Authority’s First Written Questions. Highways England also demonstrated at the meeting an interactive map of the traffic flow plots which Highways England has prepared for LBH to enable LBH to interrogate and view the changes in forecast flows for Scheme opening and design years for every link in the traffic model network within the Borough. The electronic copy of this interactive map has subsequently been passed to LBH and supplements the detailed traffic information previously issued to LBH listed below;

a) maps of flows on key routes issued to LBH on 21 August 2015,

b) an enhanced version of these maps issued on 24 September 2015,

c) the responses to questions on construction impacts and effects on M4 junctions 3 and 4 issued on 1 October 2015,

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 12 Highways England d) the technical note issued to LBH on 8 October 2015 providing further information on junction 3 traffic flows and details of schemes, developments and growth assumptions included in the traffic modelling.

1.18 The extract (included below for ease of reference) shows that in the 8-9am period, there will be an increase of just 9 movements off junction 3 on to the A312 and a reduction of vehicles along the A312.

1.19 Highways England's supporting statement included the following conclusions:

"With the scheme in place, the traffic model forecasts suggest traffic is likely to increase along the extent of the scheme in response to the improved conditions, which is illustrated by the increases in flow shown on links 1 and 8 [red boxes in diagram]. However, although the scheme ends at J3, we anticipate that there will be some increase in traffic beyond the scheme extents along the corridor as seen on links 4 and 5.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 13 Highways England The reduction in A312 traffic (link 3) appears to be mainly due to the rerouting of traffic from the current A40 / A4020 – A312 route to the improved M4 corridor, i.e. the trips currently using J3 to access M4 into London reroute and join the corridor earlier, either from J4 or even from J4b.

As a consequence, this rerouting increases the traffic on link 1 but not on link 4, as it is just a rerouting to access link 4, so link 4 would experience only a marginal increase in traffic.

A312 NB traffic (link 2) – In the DM [do minimum] scenario the trips with destinations just north of M4 J3 use the local road network, however some of these trips reroute via J3 in the DS [do something] scenario, hence a slight increase in link 2 traffic."

1.20 The Council is concerned that given the existing congestion and air quality problems in the area, there is little detail in terms of local assessment. Plainly with the extent of development coming forward in the area there will be a huge increase for demand for the A312 and connection to the M4. Indeed, the EIA Screening Report for the redevelopment of the Nestle's site (see figure 3; Cumulative Development) concludes:

"Based on initial surveys of the Bulls Bridge Roundabout [on the A312 immediately north of the M4 junction 3], it has been identified that highways improvements would be required to allow the development to distribute on to the highway network."

1.21 The implication from Highways England at the hearings is that this growth has been allowed for in their growth forecasts and therefore accounted for in the extracted diagram. However, on the face of it the conclusions on the limited amount of changes, including reductions, seem unlikely. Without disclosure of the assumptions or the detailed assessments of the local network the Council cannot support the conclusions reached.

Highways England Comment 1.21.1 Highways England acknowledges the scale of development coming forward within the Borough and is content that the amount of growth accounted for within the M4 traffic forecasts exceeds the total growth in households and employment projected within the Council’s draft Local Plan allocations for the Borough. The effects of that development on the local highway network are not a matter for Highways England. The level of growth allowed for in the traffic model growth forecasts is not implied; it is as stated in Table 2 above. The Council’s assertion on Highways England’s conclusions drawn from the model outputs are without foundation and are not backed up by any modelling. Furthermore, the small scale changes in flows referred to result from the Scheme and are separate from the effects of the development-related growth.

1.22 Furthermore, the Council is concerned that Highways England has concluded in the second bullet point (section underlined) that some of the traffic has been displaced from J3 to J4. As can be seen from the maps, the only way for this to happen is to increase traffic through Hayes and existing congested areas (seen from the air quality mapping).

1.23 In summary, the Council is concerned about the local impacts of the scheme and the lack of a robust assessment particularly factoring in the extensive growth in the area.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 14 Highways England Highways England Comment 1.23.1 In response to questions from LBH, Highways England has provided the Borough with diagrams setting out the predicted changes in flow at junctions 3 and 4 (copies of the diagrams and responses are provided at Attachment 2 to Appendix E below). From an analysis of the changes, it is correct to suggest there has been a reduction in some of the movements at junction 3 and an increase at junction 4. However, it is not correct for LBH to conclude that the only way for this to happen is to increase traffic through Hayes. The outputs from the traffic model indicate a reduction in traffic using the A437 Uxbridge Road corridor in the north-west of the Borough and on through Hayes towards the A312 and junction 3. There are corresponding increases in flow on Stockley Road to junction 4 and on the M25, suggesting re-assignment is taking place over a wider area and not through Hayes. The electronic file of traffic model outputs provided to the Borough and referred to at paragraph 1.17.1 above illustrates this point. Based on this assessment, it is Highways England’s conclusion that there are modest benefits arising from the Scheme through the sensitive area of Hayes centre, not a detrimental impact.

1.23.2 Highways England does not agree with the Council’s assertion on the robustness of the assessment or that it has not factored in planned growth for the area. Appropriate consideration has been given to the inclusion of key development sites and a validated traffic model used to undertake the assessment.

1.24 The Council would ask that Highways England discloses its assumptions for growth and how it has allowed for the planned developments by providing their modelled data of the traffic as present and the comparisons with that forecasted for 2022.

1.25 The Council would also ask that Highways England undertake a fuller local impact assessment of the implications of their scheme on the already congested local network.

Highways England Comment Traffic Growth and Model Outputs

1.25.1 Highways England has set out the assumptions for growth in its response to 1.13 above. In response to the request by LB Hillingdon for further modelled data, Highways England has provided LB Hillingdon with map-based plots of traffic forecasts output from the M4 smart motorway traffic model that cover a wide area across the Borough to illustrate the above-stated conclusions on the relative changes at junctions 3 and 4 on the M4, together with the A408 Stockley Road and A312 Parkway, both of which have been stated as particular concerns to the Borough. Highways England met with LB Hillingdon on the 21st December 2015 to discuss the Borough’s requests for further consideration of the impacts of the Scheme on its local road network. [Highways England has undertaken to continue to engage with the Council on these matters.]

1.25.2 LBH has requested that Highways England undertake assessments of unspecified junctions within the Borough on the basis that growth from NTEM be taken as ‘background growth’ and that committed development traffic be added to that to form a do-minimum against which the impact of the M4 smart motorway should then be assessed.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 15 Highways England 1.25.3 Highways England does not accept this approach as appropriate for assessment using a strategic traffic model as it is not in accordance with the treatment of uncertainty set out in paragraph 7.3.3 of TAG Unit M4 – Forecasting and Uncertainty, which states that:

a) “in order to maintain consistency with national projections, the core scenario should be based on trip end growth factors from the NTEM data set”

1.25.4 and, in paragraph 7.3.4 of TAG Unit M4 states that:

a) “NTEM also makes no assumptions about whether or not individual land use developments go ahead. Adjustments may be required based on local uncertainty assumptions, but at an appropriate spatial level growth must be constrained to NTEM to avoid optimism or pessimism bias”

1.25.5 The approach to undertaking such adjustments to account for individual land use developments is set out in paragraph 7.3.7 of Tag Unit M4 as follows:

“The TEMPRO software (described in paragraph 7.1.6) provides an alternative assumptions facility to adjust NTEM trip ends to exclude development sites (for which the trip ends will be calculated separately). This can be used as follows:

a) calculate the number of households and/or jobs in the NTEM zone resulting from developments (dwellings are often taken as a proxy for households);

b) subtract the number of subtract the number of households and/or jobs thus calculated from the zone totals in NTEM;

c) enter these data into TEMPRO (alternative planning assumptions) and rerun, to calculate the growth in trip ends excluding the developments;

d) add the development trip ends based on the Transport Assessment; and

e) check and report the total trip ends. These should be very close to the NTEM total for the given NTEM zone.”

1.25.6 Highways England considers that as NTEM takes account of projected development within each District, the additive approach to assessment suggested by LBH leads to an element of double-counting and, on that basis, Highways England does not agree with LBH.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 16 Highways England ATTACHMENT 1 TO APPENDIX E: Highways England Response to Appendix 2 of LB Hillingdon’s comments on the Examining Authority’s First Written Questions

Appendix 2- Letter sent to HE re Cumulative development

Further to your letter dated 12 December and received 24 December 2014, please find below details of schemes located within the borough that we wish to have considered as part of your ES.

It is noted that your own letter identified only 1 scheme, and for completeness, this site has been included at the top of the table below.

Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined)

Section 73 application seeking a variation to EC House, 38065/APP/2015/206 20/1/15 condition 2 (approved plans) of planning Swallowfield Way, permission ref. 38065/APP/2014/2143 (Re- Hayes development of the site to provide 5 industrial units (Use Class B1(c), B2 and B8) with associated parking, servicing and landscaping (Involving demolition and refurbishment of existing units) dated 2/12/14) to remove the 2 metre gap between units 2 and 3 by extending either or both units

Highways England Comment

Application approved after February 2014 – not included in traffic model.

The proposal is to replace an existing similar use. The applicant’s Transport Assessment (TA) concluded that “the additional traffic is insignificant” in comparison to that generated by the existing use. Total reductions: am – 47 vehicles; pm – 45 vehicles; 82 HGV’s less per day.

Highways England conclusion: Not significant – less traffic than existing use.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 17 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined)

Redevelopment of the site to provide 6 industrial Silverdale House, Pump 49670/APP/2014/3855 13/11/14 units (Use Classes B1(c), B2 and B8) and the Lane, Hayes provision of associated landscaping, parking and service space (involving demolition of existing building).

Highways England Comment

Application approved after February 2014 – not included in traffic model.

The proposal is to replace an existing similar use. The applicant’s TA estimates trip generations of: am – 15 vehicles; pm – 14 vehicles. An increase of 5 vehicles over the previous use in each peak and concluded that no assessment was necessary.

Highways England conclusion: Not significant; traffic generation under threshold for cumulative assessment.

Conversion and extension of existing office 1 Nobel Drive, 46214/APP/2014/2827 03/09/14 building to form a 200 bedroom hotel with Harlington banqueting suite, conference facilities, and rooftop restaurant, including a seven-storey extension to rear, a three storey addition at roof level, and single-storey side extension, together with the creation of a new vehicle access, and alterations to car parking and landscaping

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 18 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined)

Highways England Comment

Application approved after February 2014 – not included in traffic model.

The proposal involves a change of use. However, the applicant’s TA concludes that there will be “no significant increase in car traffic generation” (based on 283 trips per day from the hotel and 39 peak trips from the conference centre) and that the proposal “will still result in traffic far below that of the existing use.”

Highways England conclusion: Not significant – less traffic than existing use.

Determined application

Proposed mixed-use redevelopment comprising: Former London Air 5107/APP/2009/2348 Approved- 773 dwellings comprising 12 no. studios, 152 Traffic Control Centre 02/11/09 no. 1-bedroom flats, 316 no. 2-bedroom flats, 21 (NATS), Porters Way, no. 2-bedroom houses, 23 no. 3-bedroom flats, West Drayton 181 no. 3- bedroom houses, 59 no. 4-bedroom houses and 9 no. 5-bedroom houses; Class Dl Primary Healthcare facility including room for joint community use (up to 185sqm gea); Class C2 Nursing Home (up to 3630sqm gea); Classes A1-A3 Shop units to complement Mulberry Parade (up to 185sqm gea, depending on size of Primary Healthcare facility); Class B1 Business units including site management office (up to 185sqm gea); Energy Centre (up to 220sqm gea) with combined heat and power unit; foul water pumping station; associated access roads from Porters Way (and excluding all access including pedestrian and bicycle access from Rutters Close); 1085 car parking spaces; cycle parking; public open space areas; cycleways and

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 19 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined) footpaths; and landscaping works (Outline Application)

Highways England Comment

Proposal is for change of use for a comprehensive, large scale development.

Highways England conclusion: large scale development that exceeds cumulative assessment thresholds and requires explicit modelling. New zone 718 created in the traffic model to represent this site.

Stockley Park, business/office park Stockley Park, Stockley Historic extant Approved Road, West Drayton consent for industrial 1980 use

Highways England Comment

Proposal is to develop a 3rd phase of this long-established business park, for which outline consent was granted in August 2000 for 50,000m2 industrial/office/R&D use, with 1143 car parking spaces. Latest application submitted in March 2015 (37977/APP/2015/1004).

This is a significant sized development above the cumulative assessment threshold. However, the existing Phases 1 and 2 are within the traffic model based on similar business park use, together with a growth allowance for future expansion.

Highways England conclusion: historic development site adequately accounted for in traffic model zone growth projection.

Southall Gas Works redevelopment LB Ealing

Highways England Comment

Proposal is for change of use for a comprehensive, large scale residential development.

Highways England conclusion: large scale development that exceeds cumulative assessment thresholds and requires explicit modelling.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 20 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined) New zone 54 created in the traffic model to represent this site.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 21 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined)

Western International Market LB Hounslow Please confirm when the modelling work was undertaken and if it includes the recently opened Costco store and other units within the site

Highways England Comment

The International Market was relocated to an adjacent site in 2006. There are 3 current users of part of the site:

1) 9no small industrial units, (2012) 5050m2 with 26 car parking spaces. New site access & improvement to a local junction secured under planning agreement. TfL raised no objection.

2) Data Centre (2012), 15993m2; only employs 15 people. New site access secured under planning agreement. No further mitigation required.

3) CostCo (2013), 13800m2 with 538 car parking spaces. Applicant’s TA concluded that there would be minimal trips generated in the am peak and hence no impact; an additional 116 arrivals and 75 less departures compared to previous extant consents. Off- site mitigation agreed. Main impact from operation is on Saturdays.

The currently vacant balance of the site (3.2ha) has recently (30 July 2015) been allocated in the West London Waste Plan. No traffic assessment appears to have been deposited in support of the Plan. Impact of these types of development is most likely to be outside of the main traffic peaks.

Highways England conclusion: the traffic model zone representing this site has a growth allowance for 450 additional trips in the am peak and 400 in the pm peak. This is considered adequate to represent existing and future planned land uses – no explicit modelling required.

Outline planning application for a mixed use The Old Vinyl Factory, 59872/APP/2012/1838 Approved

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 22 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined) development of the Old Vinyl Factory site Blyth Road, Hayes 19/4/13 including the demolition of up to 12,643 sqm of buildings and construction of up to 112,953 sqm (112,953 sqm includes the retention and re-use of 784 sqm of the Power House and 901 sqm Pressing Plant) of new floorspace. Uses to include up to 510 residential units (maximum area of 49,000 sqm GEA), up to 7,886 sqm of new B1 floorspace, up to 4,000 sqm of A class uses (Al, A2, A3, A4, A5), up to 4,700 sqm of Dl and D2 uses, an energy centre (up to 950 sqm), car parking, works to access and creation of new accesses and landscaping

Highways England Comment

Proposal is to replace former industrial use with mixed use, including office and residential. The supporting Environmental Statement provides 2019 traffic forecasts including committed developments but nets out existing uses & notes extant consents from 2001 & 2007. It concludes that the new development flows are similar to those associated with extant consents. Forecast rip generations are: AM: 827 trips; PM: 1099 trips. Mitigation is proposed for immediate local junctions but notably excludes any reference to A312 or M4 impacts.

Highways England conclusion: the traffic model zone representing this site has a growth allowance for 1200 additional trips in each of the am peak and the pm peak periods by 2022. This is considered adequate to represent existing and future planned land uses – no explicit modelling required.

Demolition of warehouse extension to Apollo Gatefold Development, 51588/APP/2011/2253 Approved House and erection of a part 4, part 5, part 6 and Blyth Road, Hayes 27/3/12 part 7 storey building comprising 132 residential units, cafe (Class A31, community room (Class D2), S x workshop units (Class 81,58 or A2 uses), and associated car parking and landscaping

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 23 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined)

Highways England Comment

The Gatefold Development is part of overall Old Vinyl Factory ("OVF") site. Apollo House is “The Pressing Plant” unit, previously phase 1 of OVF development but subject to separate consent. The traffic impact of the Gatefold was considered as “neutral” in the OVF ES.

Highways England conclusion: the Gatefold Development is within the OVF site above for which there is adequate allowance in the traffic model and as part of that development has neutral impact – impact not significant & no explicit modelling required.

Comprehensive redevelopment of the site to 20 Blyth Road, Hayes 1425/AP/2011/3040 Approved provide a part 11, part 9, part 5 and part 4 storey 08/04/13 building comprising 120 residential units, office (Eastern end of Blyth floorspace, 97 car parking spaces and hard and Road, Hayes) soft landscaping

Highways England Comment

Proposal is to convert a former industrial site vacant since 2007 to mixed use. The residential units are proposed as ‘affordable’ flats / duplex apartments with low car ownership. The applicant’s TA suggests low level of car trip generation: AM car trips: 20; PM: 21.

Highways England conclusion: trip generation is small and adequately accounted for within growth allowance for traffic model zone 52 – no explicit modelling required.

Original consent Unit 3, Millington 32157/APP/2011/872 Planning Road, Hayes refusal Mixed use development comprising 7,310 sqm 20/4/12 (gea) industrial/warehousing unit (Use Classes Appeal B1c, B2, B8); 7998 sqm (gea) retail store (Use allowed Class Al) and petrol filling station, together with 15/11/12 associated car parking, landscaping and

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 24 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined) alterations to adjacent highway

Highways England Comment

This site occupied until late 2010 by a B8 industrial warehouse. The proposal is for a mixed use development.

The applicant’s TA estimates the trip generation as: retail trips AM: 156 vehicles; PM: 298 vehicles (TA suggests this is a robust assessment as 95% trips are already on network in the form of diverted and pass-by trips); industrial unit trip generation: AM: 86 trips; PM: 65 trips. Mitigation: improvements to 2 immediately local signal junctions.

Highways England conclusion: The net level of traffic generation is not significant and has been mitigated but in any event, sufficient allowance is already included in model zone 31 NTEM growth to cover this development.

Original consent Hyde Park Hayes, Unit 40652/APP/2012/2030 Approved - 4, Millington Road, 05/07/13 Erection of a four storey building to provide Hayes 6,966sq.m of Class 81(a) Office floorspace, provision of 70 associated car parking spaces at basement level, associated landscaping and ancillary works

Highways England Comment

Proposal is for office space to replace a previous use demolished in 2008. The applicant cited LBH previous consent for 14,000m2 B1 office in 2008. The TA estimates the trip generation as: AM: 74 trips; PM: 79 trips. A cumulative assessment was undertaken with Unit 5 (see below). Mitigation for the limited traffic impacts was achieved through changes to local junction signal timings.

Highways England conclusion: The net level of traffic generation is not significant and has been mitigated but in any event, sufficient allowance is already included in model zone 31 NTEM growth to cover this development.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 25 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined)

Original permission Hyde Park Hayes, Unit 45753/APP/2012/2029 Approved 5, Millington Road, 05/07/13 Erection of five storey building to provide Hayes 13,880sq.m of Class B1(a) Office floorspace, provision of car parking spaces at surface and basement level, associated landscaping and ancillary works

Highways England Comment

Proposal is for office floorspace and was assessed jointly with Unit 4 above in the applicant’s TA. The TA estimates trip generation as: AM: 146 trips; PM: 153 trips. Mitigation for the limited traffic impacts was achieved through changes to local junction signal timings.

Highways England conclusion: The net level of traffic generation is not significant and has been mitigated but in any event, sufficient allowance is already included in model zone 31 NTEM growth to cover this development.

S73 permission 40652/APP/2013/1981 Approved 09/09/13 Variation of condition 14 (contamination) of planning permission 40652/APP/2012/2030 granted 5 July 2013 for the Erection of a four storey building to provide 6,966 sq.m of Class 51(a) Office floorspace, provision of 70 associated car parking spaces at basement level, associated landscaping and ancillary works

Highways England Comment

Variation of conditions for Unit 4 above 40652/APP/2012/2030.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 26 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined)

Highways England conclusion: The variation in conditions covering control of contamination has no effect on traffic generation. This application is not a relevant consideration for traffic modelling.

S73 permission 45753/APP/2013/1980 Approved 09/09/13 Variation of condition 14 (contamination) of planning permission 45753/APP/2012/2029 (Erection of five storey building to provide 13,880sq.m of Class B1(a) Office floorspace, provision of car parking spaces at surface and basement level, associated landscaping and ancillary works

Highways England Comment

Variation of conditions for Unit 5 above 45753/APP/2012/2029.

Highways England conclusion: The variation in conditions covering control of contamination has no effect on traffic generation. This application is not a relevant consideration for traffic modelling.

New 3 Form of Entry primary school (630 Eastern end of Lake 68911/APP/2012/2983 Approved students) plus a nursery (45 students) and a Farm country park 14/5/13 Special Resource Provision Unit for Between Botwell Lane approximately 12 pupils, associated car parking, and Botwell Common hard and soft play areas, sports pitches, Road pedestrian and vehicular access routes and landscaping.

Highways England Comment

The development is proposed by the London Borough of Hillingdon and forms part of their policy in the LDF Core Strategy for the provision of additional capacity in the primary schools allocation. The original application 68911/APP/2012/2983 was approved (with

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 27 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined) conditions) in 2012. Several different applications have been submitted subsequently to resolve conditions stated in the original approval between 2013 and 2014. The last application 68911/APP/2014/3175 was submitted and approved in September 2014.

The TA prepared in support of the application considers local impacts over a 400m radius of school. The main traffic impact is associated with pupil drop off & pick up. Car trip generation in the am peak totals 243 vehicles, of which 215 are drop-offs. The main afternoon peak occurs between 3pm and 4pm, which does not coincide with the main traffic peak periods. Afternoon car trip generation totals 225 trips, of which 219 are pick-ups. Local traffic management measures in the form of speed control and crossing facilities are proposed in mitigation.

Highways England conclusion: the proposed school is adjacent to an established residential area. School trips are not specifically modelled within a strategic transport model; they are accounted for as part of the average trip rate for residential land uses. Accordingly, trips to primary schools would be assumed within the base model trip generation and prior to the new school being established would have been on the local network, albeit to an alternative location for the school. Furthermore, trips are assumed to be local to the school. On this basis, the development is not viewed as significant in modelling terms and has not been explicitly modelled.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 28 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined)

Change of use of existing building from office 272-276 Bath road, 464/APP/2013/2115 Approved (Use Class B1(a)) to Hotel (Use Class Cl), Heathrow, UB3 21/3/14 including 4-storey side extension (to rear of adjacent petrol station), and 4-storey rear extensions, and associated amendments to landscaping and car parking

Highways England Comment

Application approved after February 2014 – not included in traffic model.

Proposal is for a change of use from offices to a 100 bed hotel. The applicant’s TA states that there will be a neutral traffic impact when compared to the previous B1 office use. TA estimates previous use generated 115 trips per day; hotel will generate 168 trips per day. During the peak periods this will equate to 8 extra trips in am peak and 1 less in the pm peak.

Highways England conclusion: level of trip generation is not significant; no requirement for explicit modelling.

Change of use of existing building from office 272.276 Bath road, 464/APP/2014/1210 Approved (Use Class B1(a)) to 123 room Hotel (Use Class Heathrow, UB3 31/7/14 C1), including 4-storey side extension (to rear of adjacent petrol station), and 4-storey rear extensions, and associated alterations to landscaping and car parking

Highways England Comment

Application approved after February 2014 – not included in traffic model.

Proposal is for a change of use from offices to a now larger 123 bed hotel. The applicant’s TA is an update from the previous application and states that there will be a neutral traffic impact when compared to the previous B1 office use. TA estimates previous use generated 115 trips per day; hotel will now generate 207 trips per day. During the peak periods this will equate to 12 extra trips in am peak and an extra 1 in the pm peak.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 29 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined)

Highways England conclusion: level of trip generation is not significant; no requirement for explicit modelling.

Change of use of existing building from office 272-276 Bath road, 464/APP/2014/2886 Approved (Use Class B1(a)) to 136- room Hotel (Use Class Heathrow, UB3 9/1/15 Cl) and one flat for staff, including 4-storey side extension (to rear of adjacent petrol station), and 4-storey rear extensions, and associated alterations to landscaping and car parking.

Highways England Comment

Application approved after February 2014 – not included in traffic model.

Proposal is for a change of use from offices to a now larger 123 bed hotel. A similar TA was submitted as for the 123 bed application, together with the following conclusion in the applicant’s design & access statement: "It can be seen from the assessment that the trips generated by the proposed development of 138 bedrooms, as with the proposal for 100 bedrooms granted permission in 2014, whilst being more than the existing use as offices, will be of a similar scale with no material impact on the adjacent highway network.”

Highways England conclusion: level of trip generation is not significant; no requirement for explicit modelling.

Demolition of existing buildings and erection of 1 and la Bath Road, 35805/APP/2009/2433 Approved a five storey, 192 bedroom hotel, basement and Heathrow 1/2/12 surface level car parking, bar/restaurant, meeting rooms and other associated works

Highways England Comment

The proposal is to replace existing buildings with a 192 bed hotel. The original application 35805/APP/2009/2433 was approved in 2012 with a time limit of 3 years. The applicant’s TA claims a neutral traffic impact based on decrease in peaks of 25 vehicles compared to previous B1 office use.

Highways England conclusion: reduced level of trip generation compared to previous use; no requirement for explicit modelling.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 30 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined)

Erection of a part four, part five, part six storey, 276 Bath Road, 35293/APP/2009/1938 Approved 623-bedroom hotel with ancillary restaurant/bar Heathrow 28/5/10 facilities, landscaping, parking for 354 cars and associated works

Highways England Comment

Proposal is to erect a 623 bed hotel on the former Technicolour site, which relocated in 2008. The original application 35293/APP/2009/1938 was approved (with conditions) in 2009 with a time limit of 3 years. Application 35293/APP/2013/603 was submitted in March 2013 to resolve conditions 23 and 29. Not decided yet. Application 35293/APP/2013/750 was submitted in March 2013 to resolve conditions 22 and 38. Not decided yet. Application 35293/APP/2015/3693 was submitted in October 2015 for ‘minor amendment’ to original consent – change of end user to Holiday Inn/Stalybridge suites.

The applicant’s TA produced in 2009 to support the original application and not updated since estimated the trip generation as: AM: 121 trips; PM: 65 trips. The nearest junctions on the A4 were assessed and it was adjudged that there was no material impact.

Highways England conclusion: level of trip generation below threshold for specific modelling of site – no requirement for explicit modelling.

Demolition of existing hotel and erection of two Heathrow Park hotel, 3063/APP/2009/415 Approved hotels: one 4-star hotel with 250 bedrooms, and Bath Road, Longford 14/9/09 one budget hotel with 353 bedrooms, together with associated parking and landscaping

Highways England Comment

Proposal is to demolish existing (Thistle) hotel with 264 beds & erect 2 hotels with total 603 beds. A reduction in car parking spaces from 600 to 302 is proposed. Application was approved in 2009 with a time limit of 3 years.

The applicant’s TA argues that there will be a reduction in trips generated – 55 less in the am peak and 48 less in the pm peak. On this

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 31 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined) basis it was concluded there will be no traffic impact.

Highways England conclusion: no requirement to explicitly model as there will be no net impact.

Redevelopment of site to provide a 5 star luxury Airport Bowl, Bath 38807/APP/2008/3493 Approved hotel (560 rooms), a conference and ballroom Road, Heathrow 16/3/09 facility, a new 20-lane bowling centre, car parking, landscaping and associated works (including demolition of existing Airport Bowl premises and car park)

Highways England Comment

The original application 38807/APP/2008/3493 was approved in 2009 but expired in 2012. Application 38807/APP/2011/3120 was presented in December 2011 to extend the permission but was withdrawn. The applicant’s TA estimated the following trip generations: hotel: 99 trips by car per day – 10% of total; Conf. Centre: net 252 car trips/day or theatre: 168 car trips/day; bowling: 142 car trips per day. It was claimed that there would be a high proportion of linked trips. The trip generation was assessed in terms of percentage increases on the highway network and it was concluded: “This demonstrates the impact of the proposed development would represent no greater than a 5% increase on the local highway network. It is therefore considered that a more detailed junction capacity assessment is not required.”

Highways England conclusion: planning status uncertain; level of trip generation below threshold for specific modelling of site – no requirement for explicit modelling.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 32 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined)

Part outline, part full planning application for a Former Contractor's 67622/APP/2013/2532 Approved proposed hotel development of up to 660 Compound, South Of 30/7/14 bedrooms (approximately 30,000sq.m) with Swindon Road ancillary cafe, bar and restaurant facilities, car Heathrow Airport parking, service access, courtyard space, landscaping and improved ground level pedestrian access including public realm improvements (all outline application) and a perimeter veil structure wrapping around the hotel buildings (in full application detail)

Highways England Comment

Proposal is for an up to 660 bed hotel by Heathrow Airport Ltd, adjacent to T4. The applicant’s Transport Statement argues that the hotel is essentially airport-related development, serving mainly passengers in transit etc. It has limited car parking, mainly for staff use. As such it was argued trip generation was very low and no modelling of junction impacts deemed necessary.

Highways England conclusion: level of trip generation below threshold for specific modelling of site – no requirement for explicit modelling.

Demolition of existing warehouse buildings and Site Of Building 717 50657/APP/2013/2214 Approved - erection of 602 bedroom 8-storey hotel with Located Between 9/7/14 associated car parking (Outline application Sheffield Way And including details of access, appearance, layout Southern Perimeter and scale - landscaping reserved Road Heathrow Airport

Highways England Comment

The application for a 602 bed ‘budget’ hotel, near Heathrow T4. The applicant’s TA argued that “the hotel will not generally generate new trips on the highway network” (116 arrivals or departures at peak hours). It concluded that there was no net impact and no junction

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 33 Highways England Proposals Address Planning references Date Received Date (if under Approved/ consideration) Refused (if determined) assessment required.

Highways England conclusion: level of trip generation below threshold for specific modelling of site – no requirement for explicit modelling.

APPEAL BY: Heathrow Airport Limited Northern Runway, LPA REF: Refused Enabling works to allow implementation of full Heathrow Airport 41573/APP/2013/128 21/3/14 runway alternation during easterly operations at 8 Heathrow Airport including the creation of a new 'hold area' at the western end of the northern PINS REF: runway, the construction of new access and exit APP/R5510/A/14/222 taxiways, and the construction of a 5 metre high 5774 acoustic noise barrier to the south of Longford Village

Highways England Comment

LBH has agreed no assessment required as this development is only in its infancy. It is too early to consider the impact of a possible extension at Heathrow.

Projects Identified in the relevant Development Plan

Hillingdon's Local Plan: Part 2 - Site Allocations and Designations

The Council has consulted on the draft Local Plan Part 2, which ended on 4 November 2014. The next stage of the Local Plan process is submission to the Secretary of State for Communities and Local Government. A Report to Cabinet on the outcome of consultation is timetabled for March 2015 to seek agreement on the next stage of the plan making process, submission.

A copy of the document can be found on the council website by following this link: http://vAvw.hillingdon.gov.uk/media.jsp?mediaid=32151&filetype=pdf

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 34 Highways England Highways England Response

The draft Local Plan Part 2 – Site Allocations and Designations document has been reviewed in conjunction with the above listed sites.

Table 2.1 of the above document presents a summary of growth in the Borough being planned within the Local Plan Part 1 between 2011 and 2026. The following two statistics are of note:

 Total new jobs: 9000 – 11000; and

 Total new homes: 6375.

The comparative statistics within the National Trip End Model v6.2 for LB Hillingdon between 2009 (M4 smart motorway model base year) and 2022 (Scheme opening year) are:

 Total new jobs: 27,762; and

 Total new households: 8402.

Hence, the Scheme has actually modelled more trips than would have been required by the Council's own local policy.

In addition, Table 2.1 states that the projected number of additional hotel bedrooms planned between 2011 and 2026 is between 3800 and 5600. The total number of beds accounted for in the 8 hotel applications listed above in Appendix 2 is 3450. None of these hotels has been identified as having a material impact on the local highway network.

On the basis of the above, it is considered that the M4 smart motorway model takes adequate account of projected development related growth in LB Hillingdon.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 35 Highways England ATTACHMENT 2 TO APPENDIX E

M4 Junctions 3 to 12 smart motorway – Response to LB Hillingdon emails of 5th October and 7th October 2015 – updated 19th November 2015

“Thanks for this information. I will need to discuss with our traffic engineers before we can respond fully. There are some interesting patterns of traffic that warrant further scrutiny. For example, you say that the M4 will run much smoother and there is an increase in total numbers on the M4. You also accept the local road network is congested - yet the modelling shows in some instances a reduction of trips on to the M4 from supporting junctions. If the M4 is going to be a much better option than present, one would expect a scramble to get off the clogged local road networks and on to the M4 even if it is for one or two junctions. Similarly, despite the M4 being busier, in the inter peak, there is an increase of just three trips to Heathrow. This seems unlikely.

Another issue is the numbers contained in the illustrations provided. On the face of it they require further consideration. I have extrapolated the differences from the AM peak 0800-0900. The numbers in the boxes are the differences between the do minimum and do something options.

You can see there is an increase of 398 trips on the eastbound side of the M4, before junction 3. Fewer cars (-20) go north at J3 on to the 312, and fewer cars get on from the south (-43). There is a slight increase in south bound traffic to (9) and from (35). However, the figure of eastbound traffic after the junction is considerably less (312) than before the junction - this would make sense if there was a significant change to traffic entering and exit at the junction, but this is not what the illustration shows. So, where do the increased numbers go?

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 36 Highways England

I will discuss with our transport people - I may have misinterpreted it, so any assistance or explanation would be well received - but for now I think that our concerns about the interaction with the local networks have not been fully removed.” Response We have extracted some further disaggregated data from the traffic model to explain the traffic flow situation around M4 J3. In the diagram below, the numbers in the red boxes are link IDs. The numbers in yellow boxes represent the flow difference between DM and DS scenarios for the same time period analysed by LBH above, i.e. 8-9am.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 37 Highways England

 With the scheme in place, the traffic model forecasts suggest traffic is likely to increase along the extent of the scheme in response to the improved conditions, which is illustrated by the increases in flow shown on links 1 and 8. However, although the scheme ends at J3, we anticipate that there will be some increase in traffic beyond the scheme extents along the corridor as seen on links 4 and 5.

 The reduction in A312 traffic (link 3) appears to be mainly due to the rerouting of traffic from the current A40 / A4020 – A312 route to the improved M4 corridor, i.e. the trips currently using J3 to access M4 into London reroute and join the corridor earlier, either from J4 or even from J4b.

 As a consequence, this rerouting increases the traffic on link 1 but not on link 4, as it is just a rerouting to access link 4, so link 4 would experience only a marginal increase in traffic.

 A312 NB traffic (link 2) – In the DM scenario the trips with destinations just north of M4 J3 use the local road network, however some of these trips reroute via J3 in the DS scenario, hence a slight increase in link 2 traffic.

 There is a reduction in trips through J3 N-S on A312 to/from the A4 as some of these trips are now rerouting via links 1-6. This should result in a neutral flow difference on link 6. However, link 6 experiences a reduction in traffic, this is due to a reduction in traffic leaving the J3 westbound off-slip to join the A4 (to access Heathrow and surrounding area), these trips continue to travel along the improved M4 and join the A4 via M4-J4.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 38 Highways England

 The opposite happens on the A312 northbound link 7 where the A4 traffic use the A312 to access the improved M4 via J3.

 Overall, the traffic model suggests traffic will make use of the improved M4 corridor up to J3 where the scheme ends. Consequently more traffic is predicted to leave the M4 at J3 via the eastbound off slip and more traffic is predicted to join the M4 at J3 via the westbound on slip in the DS scenarios. The reverse is seen on the other two slip roads as both experience a reduction in traffic joining and leaving the motorway at J3. This pattern is repeated across all time periods and forecast years.

“I have had a chance to discuss the modelling outputs and traffic data with my colleagues. There is agreement amongst us that further information is required. The initial breakdown of the figures I provided a couple of days ago, was supplemented by work of transport colleagues who reached the same conclusion as me. The information presented is unclear on its own and we are still uncertain as to the impacts on the local road network. We are also concerned that the numbers don't quite add up and there is limited explanation as to how the modelling works. Could I therefore ask that you provide a breakdown of the assumptions, a detailed explanation of how both junctions in Hillingdon will work including why the use of the M4 would result in the reduction of movements on the A312 at certain times of the day. If you could provide the supporting information and assumptions that went into the modelling, we will then have a careful look and it might be worth further discussions following that. At present the information submitted does not allow for an adequate understanding of the impacts on the local road networks which as accepted, are highly sensitive to traffic growth.” Response: An explanation of how the traffic flows change around Junction 3 is provided above. The following section summarises the assumptions behind the modelling: Network Assumptions The table below sets out the highway schemes assumed for the forecasts. Location Base Year Coding Future Years Reduced capacity and speed limits throughout surrounding New Tunnel bypass to A3 Hindhead area associated with Hindhead with 70mph limit construction works Reduced speed limits throughout the junction and Junction remodelled with the immediate area. Reduced A33 widened through capacity due to roadworks both junction and a bus lane added. M4 Junction 11 on the A33 approaching and Normal speed limits restored. across the junction and on the Access from the junction to M4 through the junction Whitley Wood Road removed following the removal of the hard shoulder

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 39 Highways England Reduced speed limits along the Eastbound carriageway and at Normal speed limits restored M4 Junction 4B to the junction roundabout itself and increased capacity at the Junction 4 Eastbound due to roadworks associated junction roundabout. with the redesign of Junction 4

Three lanes with roadworks Roadworks completed, M25 Junction 16 to due to widening resulting in normal speeds restored and Junction 17 reduced speeds section widened to four lanes M25 Junction 17 to Three Lanes Widened to four lanes Junction 23 M25 Junction 27 to Three Lanes Widened to four lanes Junction 30 M25 Junction 5 to Junction Three Lanes Smart Motorway 7 M25 Junction 23 to Three Lanes Smart Motorway Junction 27 Replace three roundabouts Winnersh Park and Ride A 3290 Roundabouts with signals M25 anti clockwise to M4 Reduce Capacity from 2 lane westbound 2 lane slips M4 Junction 4B to 1 lane (Only part of the M25 clockwise to M4 slips) eastbound 2 lane slip Improved slip road capacity M4 Junction 10 Merge Slip roads from the M4 by adding extra merge slips to (M4/A329(M) to A329(M) NB and SB one A329(M) NB and SB to Interchange) lane capacity. relieve congestion. 3 lane for all traffic (Removal M4 J3 to J2 Bus Lane 2 Lane + 1 bus Lane of Bus Lane) Changes to Roundabout Runnymede roundabout Roundabout Layout New city Centre Layout Slough city centre Roundabout following regeneration Changes to Roundabout Bracknell Roundabout Layout

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 40 Highways England Change of layout - Roundabout near M4/J4 Roundabout elimination of a link in the middle of the roundabout Smart Motorway including improvements to the on and M3 Junction 2 to 4a Three Lanes off slips at Junction 2 with the M25, with section of the between J4-3 with 60mph.

Development Assumptions So as only to capture developments of strategic importance to the highway network, development thresholds were applied. Only developments with the following thresholds were included in the Uncertainty Log created to capture planning and infrastructure proposals:  residential over 50 residential units; and  non-residential over 1,000 square metres.

Key development sites within the Do-minimum (& Do-something) forecasts include:  Redevelopment of RAF Uxbridge site for 1340 housing units, retirement home, 90 bed hotel, 20,000sqm of mixed use commercial, primary school  Redevelopment of former NATS site for 773 dwellings  Redevelopment of Old Oak Common Sidings site for mixed employment/residential use

Growth Assumptions In line with TAG, the M4 smart motorway modelling suite employs an incremental (pivot-point) variable demand model to generate future year demand matrices.

The general approach to growth was to use National Trip End Model growth factors, controlled to District totals.

In addition, in order to capture the localised impacts of land use developments contained within the Uncertainty Log, use was made of the Alternative Planning Assumptions facility in TEMPRO whereby growth associated with explicitly modelled new developments can be taken into account. This involved:

 For each development identified in the Uncertainty Log, subtracting development households and jobs from the relevant Authority-level planning totals in TEMPRO and generating new growth factors;

 Applying adjusted TEMPRO factors to the base year HAM demand matrices;

 Adding the new development trips to the relevant zones; and

 Computing period and purpose specific TEMPRO factors in Production/Attraction format for input to the Do-Minimum.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 41 Highways England

Update 19.11.15

We have extracted some further disaggregated data from the model to explain the traffic flow situation around M4 J4.

2396 2558 30 91

2 3

14809014717 6427 14716014718 2842 1628 63332011005

6803 2895 1702 5216 11007014714 53 74 5614 376 398 1 4 J4

63336011008 2151 1721 14715063333 5655 11003018503 8 239 2159 1790 300 5 8 #N/A 68 5955

11009011010 6085 6324 7 6 69002063335 1788 2380 63334018510

1789 2467 2 87

 The numbers in yellow boxes represent the flow difference between DM and DS scenarios for AM peak (08:00-09:00). The number in the red boxes are the link IDs.

 With the scheme in place, the model suggests traffic is likely to increase along the M4 corridor, which can be seen in links 1, 4, 5 and 8. From the flow data it is clear that most of trips are through traffic via the junction (both direction) with marginal impacts to the slip road traffic.

 The increase in flow on link 2 flow appears to suggest some rerouting of traffic to local roads from the improved M4 corridor.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 42 Highways England  The increase in traffic on link 3 appears to be mainly due to rerouting of trips heading into central London from the existing M4-J3 access to M4-J4. With the improvements to M4 these trips join the M4 at J4 to take advantage of the improved capacity / speed between J4 and J3. As can be seen from the above illustration, most traffic on link 3 uses the EB on slip to access the scheme then towards central London. This has resulted in some reduction in the A312 SB traffic at M4 J3 and also on the EB on slip at J3 (details supplied earlier).

 The increase in link 6 (the access to Heathrow) suggests an increased number of trips accessing Heathrow (68 vehicles) from the east to take advantage of the improved M4 network. In addition, some of the EB off slip flow (53 vehicles) will be turning on to the Heathrow spur. In the DM scenario these trips will access Heathrow via A4 and other local access.

 Overall, traffic patterns at this junction demonstrate limited changes to the feeder road traffic (A408). Most increase is on the mainline and these trips are through the junction with potentially a positive impact to the local network.

The diagram below provides a side-by-side comparison of flows of flow changes during the early am period. The do-minimum flow is highlighted in pink; the do- something in green. The largest changes in flow are on the mainline M4 through the junction.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 43 Highways England

Paragraph 4.3 of the LBH LIR states: “It is noted that in the AM peak 07:00 to 08:00 hours eastbound traffic falls from 6,787 west of M4 junction 4 to 5,476 east of M4 junction 4, a reduction of 1,311 vehicles. It is not known whether these 1,311 vehicles are heading north to the A408 - and potentially on to Hillingdon roads (including the Heathrow Villages) or south towards Heathrow Airport.” The 1,311 vehicles are not new vehicles appearing on LBH local roads as a result of the M4 scheme. As shown in the table below, there was a reduction across the junction in the Do-Minimum case of 1,263 vehicles. This reduction increases to 1,311 in the Do-Something case, giving a net increase in vehicles turning off the M4 of 48 vehicles during that time period.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 44 Highways England

Early AM 07:00- DM 2022 DS 2022 08:00 Flow increase due to Scheme West of J4 6388 6787 399 East of J4 5125 5476 351 Reduction 1263 1311 48 Flow reductions across Junction 4: Early AM peak period Turning Movements at Junctions 4 and 3 The remainder of this Note provides details of turning movements at each of junctions 4 and 3.

Do Minimum AM Peak 08:00 -09:00 Actual flow in PCU 1 2 3 4 5 6 7 8 1 0 1,894 0 3,835 0 1,033 0 0 2 0 0 0 0 0 0 0 0 3 0 0 0 1,052 0 206 0 1,379 4 0 0 0 0 0 0 0 0 5 0 563 0 0 0 1,237 0 4,174 6 0 0 0 0 0 0 0 0 7 0 0 0 760 0 0 0 1,039 8 0 0 0 0 0 0 0 0

Do Something AM Peak 08:00 -09:00 Actual flow in PCU 1 2 3 4 5 6 7 8 Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 45 Highways England 1 0 1,931 0 4,161 0 1,061 0 0 2 0 0 0 0 0 0 0 0 3 0 0 0 1,130 0 200 0 1,395 4 0 0 0 0 0 0 0 0 5 0 565 0 0 0 1,303 0 4,416 6 0 0 0 0 0 0 0 0 7 0 0 0 762 0 0 0 1,038 8 0 0 0 0 0 0 0 0

Do Something – Do Minimum difference AM Peak 08:00 -09:00 Actual flow in PCU 1 2 3 4 5 6 7 8 1 0 37 0 326 0 28 0 0 2 0 0 0 0 0 0 0 0 3 0 0 0 79 0 -7 0 17 4 0 0 0 0 0 0 0 0 5 0 2 0 0 0 66 0 243 6 0 0 0 0 0 0 0 0 7 0 0 0 2 0 0 0 -1 8 0 0 0 0 0 0 0 0

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 46 Highways England Do Minimum AM Peak 08:00 -09:00 Actual flow in PCU 1 2 3 4 5 6 7 8 1 0 850 0 3,392 0 1,322 0 0 2 0 0 0 0 0 0 0 0 3 0 0 0 171 0 619 0 1,281 4 0 0 0 0 0 0 0 0 5 0 144 0 0 0 141 0 3,725 6 0 0 0 0 0 0 0 0 7 0 756 0 264 0 0 0 1,081 8 0 0 0 0 0 0 0 0

Do Something AM Peak 08:00 -09:00 Actual flow in PCU 1 2 3 4 5 6 7 8 1 0 939 0 3,629 0 1,400 0 0 2 0 0 0 0 0 0 0 0 3 0 0 0 100 0 557 0 1,379 4 0 0 0 0 0 0 0 0 5 0 117 0 0 0 112 0 3,777 6 0 0 0 0 0 0 0 0 7 0 700 0 181 0 0 0 1,272 8 0 0 0 0 0 0 0 0

Do Something – Do Minimum difference AM Peak 08:00 -09:00 Actual flow in PCU 1 2 3 4 5 6 7 8 1 0 89 0 237 0 77 0 0 2 0 0 0 0 0 0 0 0 3 0 0 0 -71 0 -62 0 98 4 0 0 0 0 0 0 0 0 5 0 -27 0 0 0 -29 0 52 6 0 0 0 0 0 0 0 0 7 0 -55 0 -83 0 0 0 191 8 0 0 0 0 0 0 0 0

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 47 Highways England 2396 2558 30 91

2 3

14809014717 6427 14716014718 2842 1628 63332011005

6803 2895 1702 5216 11007014714 53 74 5614 376 398 1 4 J4

63336011008 2151 1721 14715063333 5655 11003018503 8 239 2159 1790 300 5 8 #N/A 68 5955

11009011010 6085 6324 7 6 69002063335 1788 2380 63334018510

1789 2467 2 87

Figure 1. AM peak M4 J4 Link based flow difference (issued earlier).

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 48 Highways England

Figure 2. AM peak M4 J4 Turning movement based flow difference. *Numbers in the yellow boxes in the above figure represent the link based flow values from figure 1. As can be seen, there are some small differences between these values and this is due to:  Minor assignment changes from the sub-model used to extract turning movements  Link flow values are in vehicles, whereas turning movements are in PCU

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 49 Highways England

Figure 3. AM peak M4 J3 Link based flow difference (issued earlier).

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 50 Highways England

Figure 4. AM peak M4 J3 Turning movement based flow difference. *Numbers in the yellow boxes in the above figure represent the link based flow values from figure 3. As can be seen there are some small differences between these values and this is due to:  Minor assignment changes from the sub-model used to extract turning movements  Link flow values are in vehicles, whereas turning movements are in PCU.

Deadline V - Responses to Summaries of Issue Specific Hearings: LB Hillingdon - Environment Appendix E 51 Highways England