Australia

The Commonwealth funds all sorts of projects. They contributed, for example, to Brisbane City Council's big Kangaroo Point green bridge. That bridge was one of the "five green bridges" that were a major campaign promise by the LNP in 2020. Unfortunately in part due to funding "issues" (read: prioritising roads for cars), that "five" has been watered down to "three", two of which have been delivered as of today, and the third hasn't even been up for community consultation on the design or alignment yet (it was, but even that process got stopped cold and will have to be restarted from scratch after the 2022 floods caused BCC to cut all cycling funding—but, again, not road funding).

BCC should fund more of this, as you say. But they don't. And in the face of poor investment from Councils, it would be helpful if the Commonwealth were spending more than one measly dollar per person. That Commonwealth funding, even if the project itself was delivered by state and local governments, would make it easier to get more done. Maybe BCC wouldn't have cut from 5 to (maybe) 3 if they knew the Commonwealth would significantly help fund them, rather than the current begging for scraps.

As another example, the Commonwealth famously spends a lot on "black spot" funding. They should make it a condition of receiving black spot funding that the intersection and its approaches are upgraded with best practice safe cycling infrastructure (along with a robust definition of "best practice" that takes cues from successful designs from overseas, rather than relying on the current clearly inadequate definitions Australian road engineers use). Instead, a lot of black spot "upgrades" end up making the roads they're on more dangerous for cyclists.