Every metro extension announcement comes with a completion date that sounds, in hindsight, optimistic. The projects that actually hit their dates tend to share one trait: they were scoped conservatively from the start, with fewer simultaneous work fronts.

It is tempting for a city to announce a sweeping, multi-line expansion in one go. It is far harder to deliver one. The evidence from the last decade favours sequencing: finish one well-used stretch, learn from it, then extend.

None of this is an argument against ambition. It is an argument for matching ambition to execution capacity, which is the part most announcements skip.