On my phone so can't check but this may be covered by the aforementioned Not just bikes youtube series on Strong Towns, I strongly recommend checking it out. II

On my phone so can't check but this may be covered by the aforementioned Not just bikes youtube series on Strong Towns, I strongly recommend checking it out. IIRC the initial price of building roads and sidewalks was invested by the federal government at favorable terms on the condition that maintenance was covered by the municipal government. This worked great for the first 20-30 years until maintenance costs started to increase greatly towards the end of life of the infrastructure. The central theme of this series is that municipalities and towns have entered a debt trap and are relying on future growth to cover historical infrastructure debt. My explanation may be wrong, inaccurate, or not relevant for your question so I'd recommend checking out his videos if this seems interesting.