> Cities rise anyway - look at down town Seatle for a high speed example, but if you go to old cities in the UK, say Cambridge, and look at buildings 1000 years

> Cities rise anyway - look at down town Seatle for a high speed example, but if you go to old cities in the UK, say Cambridge, and look at buildings 1000 years old, they're a significant drop down from today's "ground level". Or, if you’re someplace like 1850-1860s Chicago, you just lift the entire city up a few feet to create a new ground level. This too was for infrastructure reasons, but instead of transportation, it was for a sewer/drainage system. https://en.m.wikipedia.org/wiki/Raising_of_Chicago https://en.m.wikipedia.org/wiki/Raising_of_Chicago This then repeated itself in Chicago (and elsewhere). In the twentieth century, buildings were constructed over existing (and working) rail lines. These are existing example of using air rights to hide infrastructure to make the rest of the city more livable. https://www.chipublib.org/blogs/post/technology-that-changed-chicago-air-rights/ https://www.chipublib.org/blogs/post/technology-that-changed... https://en.m.wikipedia.org/wiki/Air_rights https://en.m.wikipedia.org/wiki/Air_rights Even more recently, capping a highway was proposed by Cincinnati in their bid for Amazon’s HQ2. https://cincinnatiideas.com/2017/09/25/how-cincinnati-could-land-amazons-hq2/ https://cincinnatiideas.com/2017/09/25/how-cincinnati-could-...