The opening hinges on final accreditation from the Office of the National Rail Safety Regulator, which will assess the safety case and require sufficient time to verify risk management and safety systems before passenger services begin.

The Southwest Metro segment introduces complexities, including mechanical gap fillers for curved platforms and wildlife detection triggers within the rail corridor, influencing the progression of trials.

Historically, the project has faced delays due to regulatory approvals, with earlier opening targets for other sections of the M1 pushed back, and commuters have endured long replacement bus services since 2024 as the final segment undergoes upgrades.

Trials for driverless Metro Trains Sydney on the final 13-kilometer M1 line section between Sydenham and Bankstown have been approved, advancing toward an opening date targeted for mid-October according to confidential documents.

Metro Trains Sydney has gained approval for trial operations of driverless trains without a supervisor on board, a key step in the final testing phase.

Transport Minister John Graham emphasizes this is a rigorous, independent safety process rather than a simple approval, with data and documentation being submitted iteratively as milestones are met.

Officials caution that an opening date has not been confirmed and any date remains speculative, with the regulator needing to complete due diligence before final accreditation.