When the Metro Tunnel opens, extra services on the Cranbourne, Pakenham and Sunbury line will run between Westall Station (on the Cranbourne and Pakenham Line) and West Footscray Station (on the Sunbury Line). On weekends some services will run between Sunbury and East Pakenham stations.
From early 2026, these lines will be combined into a single Cranbourne, Pakenham and Sunbury Line which will go through the Metro Tunnel instead of the City Loop.