double road capacity along the M5 East corridor with the M8 underground tunnels running between St Peters and Kingsgrove
join these underground routes together via the M4–M5 Link tunnel to form a seamless motorway without traffic lights
provide a western bypass of the Sydney CBD; and
provide connections to the future Western Harbour Tunnel, Beaches Link, M6 extension and major international gateways at Sydney Airport and Port Botany.