The re-signalling of the Victoria line and introduction of distance-to-go automatic train operation was a major London Underground (LU) project completed in time for the 2012 Olympics. The development and re-signalling was carried out by Invensys Rail Limited (IRL) in collaboration with the train builder (Bombardier) and LU, and was unique in both its design and implementation. The upgrade aims were to deliver a complete re-signalling replacement whilst minimising service disruption. This was achieved via a staged overlay system which was implemented as a hybrid signalling system, controlling both existing and new rolling stock simultaneously. This provided considerable assurance challenges in both managing the system hazards and system approvals. This paper focuses on the management of the staged project delivery whist tracking and maintaining a robust safety argument.