The Western Harbour Tunnel proposal involves the construction of a motorway crossing underneath Sydney Harbour, connecting WestConnex with the Warringah Freeway.
Travel demand across Sydney Harbour is projected to increase, resulting in further congestion. The Gore Hill/Warringah Freeway/Sydney Harbour Bridge/Eastern Distributor Corridor is projected to become the 10th most congested corridor in Sydney in 2031. Congestion on this corridor impacts on bus and private vehicle travel. The high levels of demand for existing infrastructure reflects the channeling of traffic onto the Sydney Harbour Bridge and Tunnel across Sydney Harbour.