Hint: Inventions
Inventions occur in this game around certain decades. Usually, the inventions listed below will happen within a decade (on both sides) of the date listed for your use.

Arcologies - 2000/2050/2100/2150
Buses/Bus Depot - 1920
Desalinization Plant - 1990
Fusion Power Plant - 2050
Gas Power Plant - 1950
Highways - 1930
Microwave Power Plant - 2020
Nuclear Power Plant - 1955
Solar Power Plant - 1990
Subway System - 1910
Water Treatment Plant - 1935
Wind Power Plant - 1980


Submitted by Shadow87Terrorist