Draft A27 Chichester Bypass Mitigation Supplementary Planning Document (SPD) Version 2 - May 2024

Section 4 – Planning Contributions (Parts 4.5 / 4.9 / 4.14)
Whilst the principles the Council is promoting to secure financial contributions to the improvement of the A27 (to mitigate the impact of growth) is fully supported, the approach presented does not properly and fairly reflect the requirements of the CIL Regulations (122) in promoting a fair and reasonable approach to the calculation of contributions or collection of funds. Specific commentary on relevant matters is outlined:
Part 4.5 – Target Contribution Level
The SPD approach is predicated on achieving a target contribution level of £8,000 per dwelling, which the Council states is concluded to be ‘viable for most development typologies’.
However, this approach takes no account of the impact of possible alternative funding sources on the requirement for funding in the first place. The A27 is an example where the relevant authorities (including CDC, WSCC and NH) are actively engaged in seeking long term improvements which may well lead to achieving funding from other sources, such as through National Highway’s RIS3 programme, or various future funding opportunities the new government may bring.
If external funding (i.e. RIS 3) were to be achieved for the improvements, the funding requirement may be lesser to that which informed this target contribution level, rendering the SPD approach unsuitable.
Part 4.9 – Use of Car Ownership Rates as proxy
The methodology for calculating contributions has been updated from the earlier SPD draft to now consider car ownership levels (at ward level), which it uses as a proxy for car trips and so traffic impact. This is justified by the Council on the basis it considers that car ownership rates will be influenced by site proximity to a good range of amenities or good sustainable transport links, so reflect likely impact.
There are two concerns with this approach:
• This approach considers that forthcoming development would replicate the existing development of the area within which it is located (and which generates the car ownership rate applied in the SPD Apportionment).
In many cases this will not be true with new development often comprising a different housing mix, density, and sustainability to the existing development in the area it is located. The ward areas used to establish car ownership in some cases are very large and comprise rural villages and settlements, albeit on the very edge of Chichester. New development would not likely reflect existing patterns in relation to car ownership and sustainability. Applying existing car ownership rates without reflecting the difference of new modern development is unsound.
• The application of car ownership rates as the proxy for apportionment makes no allowance for the delivery of mixed-use developments and sustainable transport schemes as part of development proposals which would reduce traffic demands on the A27 corridor. The Drayton Water (A8) site is one such example that would see housing delivered alongside a primary school, local centre, open spaces and community facilities, and follows a Vision based approach. This will serve to reduce the vehicle impact of the scheme which is not reflected in the approach promoted.
Therefore, the approach seeks contributions which would fail to meet the CIL Reg 122 tests by not being proportional in scale to the impact of development.
Part 4.14 – Target Contribution Level
The SPD seeks planning contributions from only residential uses and those only located within the south of the district. This fails to reflect the impact of wider residential and non-residential development in contributing to pressures on the A27 corridor, and so informing the calculation of the SPD contribution.
This approach is flawed and disproportionately loads the cost of infrastructure improvements on the A27 on specific residential developments in only parts of the district, without key traffic generators (for example commercial development) being required to mitigate the impact it creates, and without requiring cross-boundary development to mitigate its impact in Chichester.
In particular, the SPD approach does not seek to fairly and reasonably mitigate for the following types of development which will impact on the A27 corridor:
- Development in the north of the district – The A27 is a strategic route used across the sub-region. Development across the whole district will impact on its requirement for improvement and funding should be captured more widely.
- Development in neighbouring districts (i.e. Havant BC and Arun DC). The SPD recognises that growth in Chichester district is only one contributor to issues on the A27 which carries significant through traffic. By failing to recognise this in the approach to generate funding to improve the A27 corridor, the proposed SPD approach is unreasonable and burdens development in southern Chichester to address an issue it does not create alone.
- Non-residential development, such as commercial / employment – Employment uses particularly will generate traffic and impact on the A27 corridor yet are not required to fund improvements to mitigate the impact it creates. Whilst employment development can seek to rebalance traffic flows and commuting patterns, many types of commercial development would result in net traffic impacts on the A27 corridor and should reasonably be required to contribute to its improvement in the same manner as residential development.
he following changes are recommended to the SPD to address the soundness issues.
Part 4.5 – Target Contribution Level
The SPD should be amended to allow for the re-calculation of the target contribution level if alternative funding sources were identified and secured.
Part 4.9 - Use of Car Ownership Rates as proxy
SPD contributions should be attributed to an external vehicle trip rate, which would be a truer reflection of the likely impact on the A27 asset the SPD seeks to mitigate and improve. It is acknowledged that for smaller windfall sites there may not be a Transport Assessment produced and as such a benchmark trip rate for these schemes could be applied. However, for larger schemes, the SPD should reflect that the impacts of development will be determined through a Transport Assessment, which should form the basis of any contribution assessment.
Part 4.14 – Target Contribution Level
The SPD should be amended to:
- Capture contributions from the northern part of the District through applying a ‘Rest of Chichester’ apportionment and requirement to secure funding.
- Commit to seeking contributions from adjacent and nearby authorities where development proposals are shown to impact on the A27 corridor and contribute to its need for improvement.
- Include a contribution requirement on non-residential developments to secure proportionate funding to the impact these create.

Section 4 – Planning Contributions (Parts 4.5 / 4.9 / 4.14)
Whilst the principles the Council is promoting to secure financial contributions to the improvement of the A27 (to mitigate the impact of growth) is fully supported, the approach presented does not properly and fairly reflect the requirements of the CIL Regulations (122) in promoting a fair and reasonable approach to the calculation of contributions or collection of funds. Specific commentary on relevant matters is outlined:
Part 4.5 – Target Contribution Level
The SPD approach is predicated on achieving a target contribution level of £8,000 per dwelling, which the Council states is concluded to be ‘viable for most development typologies’.
However, this approach takes no account of the impact of possible alternative funding sources on the requirement for funding in the first place. The A27 is an example where the relevant authorities (including CDC, WSCC and NH) are actively engaged in seeking long term improvements which may well lead to achieving funding from other sources, such as through National Highway’s RIS3 programme, or various future funding opportunities the new government may bring.
If external funding (i.e. RIS 3) were to be achieved for the improvements, the funding requirement may be lesser to that which informed this target contribution level, rendering the SPD approach unsuitable.
Part 4.9 – Use of Car Ownership Rates as proxy
The methodology for calculating contributions has been updated from the earlier SPD draft to now consider car ownership levels (at ward level), which it uses as a proxy for car trips and so traffic impact. This is justified by the Council on the basis it considers that car ownership rates will be influenced by site proximity to a good range of amenities or good sustainable transport links, so reflect likely impact.
There are two concerns with this approach:
• This approach considers that forthcoming development would replicate the existing development of the area within which it is located (and which generates the car ownership rate applied in the SPD Apportionment).
In many cases this will not be true with new development often comprising a different housing mix, density, and sustainability to the existing development in the area it is located. The ward areas used to establish car ownership in some cases are very large and comprise rural villages and settlements, albeit on the very edge of Chichester. New development would not likely reflect existing patterns in relation to car ownership and sustainability. Applying existing car ownership rates without reflecting the difference of new modern development is unsound.
• The application of car ownership rates as the proxy for apportionment makes no allowance for the delivery of mixed-use developments and sustainable transport schemes as part of development proposals which would reduce traffic demands on the A27 corridor. The Drayton Water (A8) site is one such example that would see housing delivered alongside a primary school, local centre, open spaces and community facilities, and follows a Vision based approach. This will serve to reduce the vehicle impact of the scheme which is not reflected in the approach promoted.
Therefore, the approach seeks contributions which would fail to meet the CIL Reg 122 tests by not being proportional in scale to the impact of development.
Part 4.14 – Target Contribution Level
The SPD seeks planning contributions from only residential uses and those only located within the south of the district. This fails to reflect the impact of wider residential and non-residential development in contributing to pressures on the A27 corridor, and so informing the calculation of the SPD contribution.
This approach is flawed and disproportionately loads the cost of infrastructure improvements on the A27 on specific residential developments in only parts of the district, without key traffic generators (for example commercial development) being required to mitigate the impact it creates, and without requiring cross-boundary development to mitigate its impact in Chichester.
In particular, the SPD approach does not seek to fairly and reasonably mitigate for the following types of development which will impact on the A27 corridor:
- Development in the north of the district – The A27 is a strategic route used across the sub-region. Development across the whole district will impact on its requirement for improvement and funding should be captured more widely.
- Development in neighbouring districts (i.e. Havant BC and Arun DC). The SPD recognises that growth in Chichester district is only one contributor to issues on the A27 which carries significant through traffic. By failing to recognise this in the approach to generate funding to improve the A27 corridor, the proposed SPD approach is unreasonable and burdens development in southern Chichester to address an issue it does not create alone.
- Non-residential development, such as commercial / employment – Employment uses particularly will generate traffic and impact on the A27 corridor yet are not required to fund improvements to mitigate the impact it creates. Whilst employment development can seek to rebalance traffic flows and commuting patterns, many types of commercial development would result in net traffic impacts on the A27 corridor and should reasonably be required to contribute to its improvement in the same manner as residential development.
he following changes are recommended to the SPD to address the soundness issues.
Part 4.5 – Target Contribution Level
The SPD should be amended to allow for the re-calculation of the target contribution level if alternative funding sources were identified and secured.
Part 4.9 - Use of Car Ownership Rates as proxy
SPD contributions should be attributed to an external vehicle trip rate, which would be a truer reflection of the likely impact on the A27 asset the SPD seeks to mitigate and improve. It is acknowledged that for smaller windfall sites there may not be a Transport Assessment produced and as such a benchmark trip rate for these schemes could be applied. However, for larger schemes, the SPD should reflect that the impacts of development will be determined through a Transport Assessment, which should form the basis of any contribution assessment.
Part 4.14 – Target Contribution Level
The SPD should be amended to:
- Capture contributions from the northern part of the District through applying a ‘Rest of Chichester’ apportionment and requirement to secure funding.
- Commit to seeking contributions from adjacent and nearby authorities where development proposals are shown to impact on the A27 corridor and contribute to its need for improvement.
- Include a contribution requirement on non-residential developments to secure proportionate funding to the impact these create.

Section 4 – Planning Contributions (Parts 4.5 / 4.9 / 4.14)
Whilst the principles the Council is promoting to secure financial contributions to the improvement of the A27 (to mitigate the impact of growth) is fully supported, the approach presented does not properly and fairly reflect the requirements of the CIL Regulations (122) in promoting a fair and reasonable approach to the calculation of contributions or collection of funds. Specific commentary on relevant matters is outlined:
Part 4.5 – Target Contribution Level
The SPD approach is predicated on achieving a target contribution level of £8,000 per dwelling, which the Council states is concluded to be ‘viable for most development typologies’.
However, this approach takes no account of the impact of possible alternative funding sources on the requirement for funding in the first place. The A27 is an example where the relevant authorities (including CDC, WSCC and NH) are actively engaged in seeking long term improvements which may well lead to achieving funding from other sources, such as through National Highway’s RIS3 programme, or various future funding opportunities the new government may bring.
If external funding (i.e. RIS 3) were to be achieved for the improvements, the funding requirement may be lesser to that which informed this target contribution level, rendering the SPD approach unsuitable.
Part 4.9 – Use of Car Ownership Rates as proxy
The methodology for calculating contributions has been updated from the earlier SPD draft to now consider car ownership levels (at ward level), which it uses as a proxy for car trips and so traffic impact. This is justified by the Council on the basis it considers that car ownership rates will be influenced by site proximity to a good range of amenities or good sustainable transport links, so reflect likely impact.
There are two concerns with this approach:
• This approach considers that forthcoming development would replicate the existing development of the area within which it is located (and which generates the car ownership rate applied in the SPD Apportionment).
In many cases this will not be true with new development often comprising a different housing mix, density, and sustainability to the existing development in the area it is located. The ward areas used to establish car ownership in some cases are very large and comprise rural villages and settlements, albeit on the very edge of Chichester. New development would not likely reflect existing patterns in relation to car ownership and sustainability. Applying existing car ownership rates without reflecting the difference of new modern development is unsound.
• The application of car ownership rates as the proxy for apportionment makes no allowance for the delivery of mixed-use developments and sustainable transport schemes as part of development proposals which would reduce traffic demands on the A27 corridor. The Drayton Water (A8) site is one such example that would see housing delivered alongside a primary school, local centre, open spaces and community facilities, and follows a Vision based approach. This will serve to reduce the vehicle impact of the scheme which is not reflected in the approach promoted.
Therefore, the approach seeks contributions which would fail to meet the CIL Reg 122 tests by not being proportional in scale to the impact of development.
Part 4.14 – Target Contribution Level
The SPD seeks planning contributions from only residential uses and those only located within the south of the district. This fails to reflect the impact of wider residential and non-residential development in contributing to pressures on the A27 corridor, and so informing the calculation of the SPD contribution.
This approach is flawed and disproportionately loads the cost of infrastructure improvements on the A27 on specific residential developments in only parts of the district, without key traffic generators (for example commercial development) being required to mitigate the impact it creates, and without requiring cross-boundary development to mitigate its impact in Chichester.
In particular, the SPD approach does not seek to fairly and reasonably mitigate for the following types of development which will impact on the A27 corridor:
- Development in the north of the district – The A27 is a strategic route used across the sub-region. Development across the whole district will impact on its requirement for improvement and funding should be captured more widely.
- Development in neighbouring districts (i.e. Havant BC and Arun DC). The SPD recognises that growth in Chichester district is only one contributor to issues on the A27 which carries significant through traffic. By failing to recognise this in the approach to generate funding to improve the A27 corridor, the proposed SPD approach is unreasonable and burdens development in southern Chichester to address an issue it does not create alone.
- Non-residential development, such as commercial / employment – Employment uses particularly will generate traffic and impact on the A27 corridor yet are not required to fund improvements to mitigate the impact it creates. Whilst employment development can seek to rebalance traffic flows and commuting patterns, many types of commercial development would result in net traffic impacts on the A27 corridor and should reasonably be required to contribute to its improvement in the same manner as residential development.
he following changes are recommended to the SPD to address the soundness issues.
Part 4.5 – Target Contribution Level
The SPD should be amended to allow for the re-calculation of the target contribution level if alternative funding sources were identified and secured.
Part 4.9 - Use of Car Ownership Rates as proxy
SPD contributions should be attributed to an external vehicle trip rate, which would be a truer reflection of the likely impact on the A27 asset the SPD seeks to mitigate and improve. It is acknowledged that for smaller windfall sites there may not be a Transport Assessment produced and as such a benchmark trip rate for these schemes could be applied. However, for larger schemes, the SPD should reflect that the impacts of development will be determined through a Transport Assessment, which should form the basis of any contribution assessment.
Part 4.14 – Target Contribution Level
The SPD should be amended to:
- Capture contributions from the northern part of the District through applying a ‘Rest of Chichester’ apportionment and requirement to secure funding.
- Commit to seeking contributions from adjacent and nearby authorities where development proposals are shown to impact on the A27 corridor and contribute to its need for improvement.
- Include a contribution requirement on non-residential developments to secure proportionate funding to the impact these create.