Railroad Tycoon and Railroad Tycoon 2 are two of my all time favourite games. Along with Sid Meier's Colonization, they are actually the only games that I've gone back to time after time for years.

Ok, maybe not an iteration then. But Sawyer drew inspiration from Raiload Tycoon and wanted an isometric version. Then it was natural marketing to publish Transport Tycoon with MicroProse. source: https://www.filfre.net/2020/10/transport-tycoon/

Sid Meier and Will Wright (Sim City) had the system simulators in 2D, and I wonder whether Sawyer influenced them with the isometric world from Transport Tycoon.