Modelling changes to the transport network

The second sensitivity test involved modelling changes to the transportation network. This was achieved by modelling a hypothetical bridge across the mouth of the Avon – Heathcote Estuary (figure 16.5).

Figure 16.5   Modelled bridge across the Avon – Heathcote Estuary


This test was performed both at meshblock level, to provide an overall picture of the city-wide impacts, and then at a higher resolution for the properties in the suburbs of South Brighton and Sumner. A summary of the change in consumed accessibility due to the bridge at the level of individual parcels is shown in figure 16.6. The full results are presented in appendix F3.

Figure 16.6   Change in accessibility due to inclusion of a bridge over the Avon – Heathcote Estuary

Fig 5_6

The results show a dramatic increase in accessibility to doctors, primary schools and supermarkets for the southern tip of the Brighton Spit with the greatest improvements for all of these being approximately 0.5. At the same time, there are some positive benefits (0.01–0.2) for the residents of Sumner.

Minor improvements (0.01–0.2) are seen for hospitals, secondary schools and further education facilities for the southern tip of Brighton Spit. This is due to the fact these facilities are already quite distant from both sides of the bridge and the magnitude of the travel time savings to these facilities due to the new bridge is minimal.

The magnitude of the change in the comprehensive accessibility score ranges between 0 and 0.4, with the maximum benefit occurring for residents on the southern tip of the Brighton Spit (figure 16.6).