Public infrastructure means any infrastructural capital under public ownership - that is, any such capital asset that is not firm-specific infrastructure.

It is a very general term which should almost always be qualified specifically as

• public works which is the nearest equivalent term but often describes the maintenance functions, accounting treatment and agencies, not just the structures, e.g. "Canadian Public Works Association "
• critical infrastructure required to sustain human life
• urban infrastructure supporting large masses of people
• rural infrastructure connecting much sparser settlements
• municipal infrastructure under local government control
  • sustainable municipal infrastructure thought to move in the direction of sustainability, specifically:
    • sustainable rural infrastructure
    • sustainable urban infrastructure

depending on which aspect of public management is under scrutiny. Military assets may also be considered to be public infrastructure, though infrastructure does not in most cases include or imply weapons or active security - infrastructure is usually what is protected, not what protects.