A27 Chichester Bypass Mitigation Supplementary Planning Document - August 2023

• The CATM model has been validated and calibrated using 2014 counts. Using 2014 data means that significant changes such as the opening of Chichester Free School immediately next to the A27 Whyke roundabout, with over 1000 pupils and over 140 staff may not have been considered.

• This data is now 9 years old.
 
• The Transport Assessment states that "it should be noted that even prior to adding in the Local Plan development, all the junctions on the A27 Chichester bypass are over capacity in one or both modelled peak hours. With the exception of Portfield Roundabout, the junctions are also shown to be over or very near capacity in the base year model (2014) before any additional background or Local Plan traffic is added, highlighting the fact that it is not just the Local Plan or committed Chichester development which leads to this situation." 

Whilst only 28% of traffic growth can be linked to committed and proposed Local Plan developments, if the mitigation measures only apply to Fishbourne and Bognor roundabouts, then the problem with over capacity still remains. 

Therefore, the plan is not effectively mitigating the impact of the addition growth and is adding further demands on capacity which is already exceeded, therefore the housing number should be challenged further.

Under the monitor and manage aspects to the A27 junctions, the Local Plan states that a Traffic and Infrastructure Management Group (TIMG) will be set up to oversee the delivery of this process. Improvements to the A27 have been contentious in the past, with the DfT public consultation in 2016 as part of Road investment strategy 1 (RIS1), resulting in no consensus from the consultation feedback on which option should be taken forward. The Local Plan consultation in 2018, also raised significant feedback on the proposed changes to the A27, particularly regarding restricting local movements at key junctions and the Stockbridge Link Road, where the proposals were similar to those options robustly rejected in the RIS 1 consultation. The Local Plan does not provide any details on how representatives will be selected to be part of TIMG, nor how local residents will be consulted on the delivery of any changes as part of the monitor and manage process. This therefore, could present an opportunity for circumventing legitimate local concerns and feedback on any proposals to be delivered under this group.