A27 Chichester Bypass Mitigation Supplementary Planning Document - August 2023

Background

The need for A27 Chichester Bypass improvements

2.1 The A27 is part of the Strategic Road Network and is therefore the responsibility of National Highways. Other roads within the District are the responsibility of West Sussex County Council (WSCC). Road congestion is a major concern for residents and businesses in the District; in particular, congestion around the junctions of the A27 Chichester Bypass. This in turn, leads to congestion on the local road network as drivers seek alternative routes, leading to further traffic-related problems on those alternative routes.

2.2 The Local Plan (2014 – 2029) acknowledges that without mitigation, new housing and employment proposed in the Local Plan would increase this congestion further, leading to increased queuing times around the A27 junctions and within Chichester city and a deterioration in highway safety. In response, Policy 8 (Transport and Accessibility) made provision for a coordinated package of improvements to junctions on the A27 Chichester Bypass that will increase road capacity, reduce traffic congestion, improve safety, and improve access to Chichester city from surrounding areas.

2.3 The basis for securing funding for A27 improvements to address the impact of the planned development identified over the plan period is set out in Policy 9 (Development and Infrastructure Provision). This explains that the Infrastructure Delivery Plan will be used to identify the timing, type and number of infrastructure requirements to support the objectives and policies of the Local Plan as well as the main funding mechanisms and lead agencies responsible for their delivery. Further, Policy 9 requires that all development, where appropriate, mitigates the impact of the development on existing infrastructure, facilities or services.

The 2016 Planning Obligations & Affordable Housing SPD

2.4 At the time the Local Plan was adopted, the relevant evidence base included the Transport Study of Strategic Development Options and Sustainable Transport Measures (2013) which identified an indicative package of measures for the six junctions on the Bypass, costing £12.82 million. These measures were identified as being sufficient to mitigate the impact of development proposed in the Local Plan. On this basis, the 2016 Planning Obligations & Affordable Housing SPD had the objective of securing £11.17 million in development contributions over the lifetime of the Local Plan. The remainder of the identified funding had already been secured by the time the 2016 SPD was adopted, specifically for the identified improvement works to Portfield Roundabout and Oving Road junction. Both of these junction improvements have since been completed.

2.5 Monitoring has indicated that £3.37 million in contributions has been collected since 2016 from development coming forward in the south of the district in accordance with the 2016 SPD. In addition, there is a further £3.67 million has been secured through signed S106 agreements for developments that have yet to commence or where payment triggers are not yet reached. A further £9.22 million in contributions is also in the process of being secured under the 2016 SPD from the Strategic Development Locations at West of Chichester (Phase 2) and Tangmere, each of which are yet to be granted planning permission. The combined total of these sums was £16.25 million at August 2023.

2.6 Although the 2016 SPD has been successful in securing more than the target level of developer contributions for A27 improvement works, the remaining improvement works to the Fishbourne, Bognor, Stockbridge and Whyke roundabouts have not been possible to deliver. The main reason for this is that the cost of delivering these improvement works has increased very significantly over the past decade, well beyond the level of funding that has been secured through planning contributions under the 2016 SPD.

2.7 The Council has continued to press for improvements to the A27 Chichester Bypass to be addressed by central government funding and there has been continual engagement between the Council and National Highways over the past decade seeking to achieve this end. However, in spite of these efforts, no other sources of funding have been made available to address the shortfall from the funding secured through development contributions.

Updated technical evidence

2.8 Evidence produced to inform the emerging Local Plan 2021 -2039 has demonstrated that a number of the Chichester Bypass junctions are already over capacity, even without further planned development^[1]. Therefore, in order to address the impact of further cumulative development on an already overburdened A27 Chichester Bypass, a new mitigation package involving improvements to all six of the A27 junctions surrounding Chichester City was designed and has been agreed with National Highways and WSCC.

2.9 Taking account of the improvements at Portfield and Oving junctions which have already been funded and completed, the remaining identified improvements involved Bognor, Whyke, Stockbridge and Fishbourne junctions. Work has been undertaken to cost these improvements and this has been subject to review by National Highways and WSCC. Following this work, the latest available cost estimate for the full package of improvements is between £86.14 million and £126.11 million^[2].

Response to the updated evidence base

2.10 Following local plan viability testing, and in light of the absence of any alternative sources of funding, the Council resolved at its meeting in July 2021 that the full package of A27 improvements, described above, is undeliverable. Therefore, the decision was taken to adopt an 'infrastructure constrained' approach to delivery of the new Local Plan; i.e. one would investigate what level of development could be brought forward with the maximum level of junction mitigation that would be affordable through developer contributions alone.

2.11 Working with National Highways and WSCC, the most effective (and financially achievable) solution is to deliver the Fishbourne and Bognor junction improvements alongside a 'Monitor and Manage' approach, to try to provide additional reductions in trips on the network through sustainable transport measures and other small-scale local highway network interventions that will be identified through the Monitor and Manage process. This process will be run through a 'Traffic and Infrastructure Management Group' (TIMG) which will be set up, consisting of representatives from the Council, WSCC and National Highways.

2.12 The 'infrastructure constrained' approach, which is being taken forward due to the absence of funding for the full A27 mitigation package, anticipates the delivery of Fishbourne junction improvement first, likely to be followed by Bognor junction improvement later in the emerging Plan Period. At present these two junction improvements have a combined cost within a range of up to £43.3 million.

The need for a revised approach to securing planning obligations

2.13 National Highways considers that the 'baseline' for determining the additional impact on the A27 caused by new development was January 2023. This was the date when the Local Plan Transport Assessment was published, alongside the Proposed Submission Plan. Due to the prospect of only a reduced package of infrastructure improvements being deliverable over the coming Plan Period, the Council has needed to propose a lower level of development within the emerging Local Plan as part of the 'infrastructure constrained approach'. This amounts to a limit of 9,630 dwellings to 2039 in the south of the District. Whilst the precise number of new homes that can be mitigated by the reduced infrastructure package is a matter for the Local Plan Examination, there is already an effective ceiling or cap on new residential development. Therefore, any new dwellings coming forward now within the south of the district, whether permitted by the Council or on Appeal, place a cumulative impact upon the A27, which the proposed reduced level of junction improvements is seeking to address.

2.14 As set out above, the latest available cost estimate of the Fishbourne and Bognor junction improvements sits within a range of up to £43.3 million. From this total we deduct the £16.25 million in developer contribution receipts secured under the 2016 SPD. This leaves about £27 million to be funded through further as yet uncommitted development. This will be either identified through the local plan process, or arise from planning permissions for further housing development in the interim.

2.15 In order to determine whether securing £27 million in developer contributions would be feasible, local plan viability testing was undertaken to support the Proposed Submission Plan^[3]. This tested potential financial contributions for A27 mitigation at various levels ranging from £3,000 to £8,000 per dwelling. The outcome of the viability testing was that the majority of development scenarios across the south of the District were found to be sufficiently viable at a contribution level of up to £8,000 per dwelling.