- Building above ground is easier. But if you're building below ground, bedrock is easier than e.g. alluvial soil or sandy soil. https://pedestrianobservations.

- Building above ground is easier. But if you're building below ground, bedrock is easier than e.g. alluvial soil or sandy soil. https://pedestrianobservations.com/2020/11/23/more-on-station-costs/ https://pedestrianobservations.com/2020/11/23/more-on-statio... - NYC is a brand new city compared to pretty much everywhere but the American West. We're talking about comparisons to Rome here, not comparisons to LA. And Rome is about 3x cheaper to build in than LA, which is about 3x cheaper than NYC. https://transitcosts.com/what-does-the-data-say/ https://transitcosts.com/what-does-the-data-say/