The third continental phase completes the six-corridor 20,000km network. SBC #5 Derby to Esperance and SBC #6 Albany to Port Douglas — two corridors that close the network on the western side and provide the final continental connectivity. With Phase 3 complete, the SBC network is operational across the full continent.
Phase 3 closes the continental network. SBC #5 runs north–south through Western Australia from Derby in the Kimberley to Esperance on the south coast. SBC #6 runs as a long arc from Albany on the WA south coast all the way to Port Douglas in tropical Queensland — completing the network with the longest single corridor in the programme.
| SBC #5 | Derby to Esperance — ~1,800km — Western Australia north–south corridor connecting the Kimberley to the south coast |
| SBC #6 | Albany to Port Douglas — ~2,700km (longer if routed via the interior) — long-arc corridor closing the continental network from south-west to far north-east |
| Configuration | MMC-VA — dual-leg, five-level viaduct (the full continental standard) |
| Strategic role | Network completion — final continental connectivity, full six-corridor 20,000km operational network |
| Status | Proposed — project scope and engineering memos to follow Phase 2 commitment |
Route alignment is indicative. The corridor shown on the project map is a suggested alignment based on the current planning case. Final geometry is subject to detailed engineering — terrain survey, geotechnical analysis, environmental and cultural heritage assessment, and stakeholder consultation will determine the final alignment at detailed design.
Phase 3 project scope is determined following Phase 2 operational commitment. SBC #5 and SBC #6 corridor specifications, sequencing, and engineering memos will be added here as the programme matures.