Hack for Acrophobics: No More Glass Roads in New York City
— Read on zwiftinsider.com/no-glass-roads/
Read about the NoMoreGlassRoads hack by Jonathon Levie at Zwift Insider. It has instructions for Windows.
For macOS the corresponding location to put the files would be ~/Library/Application Support/Zwift/data/Environment/Road
Feel free to try if it works or not…