Public infrastructure projects gain authorization on account of strategic promises that must stay understandable even after the project has undergone front-end formulation, design, construction, commissioning, and operational use. This paper explores how phase gates adjacent to one another affect the visibility and custodianship of discontinuity modes in a change programme for a public infrastructure project and what owner-side continuity obligations are implied. The dataset consists of a fixed phase-mode ledger of a Norwegian public infrastructure authority comprising twenty coded cases: seven in the front-end, one in design, nine in construction, and three in operation. Mode distribution includes one personnel case, seven information cases, five measurement cases, and seven strategy cases. Four calculated criteria are used for analysis: Boundary-Weighted Continuity Potential (BWCP), Directional Gate-Retention Analysis (DGRA), Custody-Span Orphan Test (CSOT), and Continuity Activation Score (CAS). The results demonstrate that construction bears the heaviest discontinuity burden and the front-end shows the widest variety of discontinuity modes. Information and strategy prove the most frequent modes (35% each), although measurement boasts the highest boundedness-weighted priority due to four of its five cases occurring in construction. The design-construction gate features the lowest retained profile share (\(R=0.222\)), followed by front-end-design (\(R=0.286\)), although construction-operation maintains a higher aggregate profile share (\(R=0.556\)) but loses measurement completely. CSOT reveals that measurement stands out as the sole mode that reaches an orphan rate of \(\Omega=1.000\), while information appears visible in all phases yet demonstrates a major change in relative salience (\(A=0.646\)). According to CAS, measurement takes the first place (\(0.672\)), followed by strategy (\(0.460\)), information (\(0.323\)), and personnel (\(0.190\)). Therefore, the research question receives an exact answer: strategic continuity is not lost exclusively at final handover; it gets filtered at design-construction, reconstructed in construction, and jeopardized at operation when the custody of measurement is not continued. The owners of public infrastructure must consider measurement covenanting, strategic custody, evidence harmonization, and role backup as separate continuity obligations and not as a checklist.