Civilization manualBook 1: From Bare Hands to Steam and Electricity765 entries · 23 phases · 100 years
The Island
Phase 19 — Roads, bridges, flyovers and tall buildings  /  About year 72
19.22

Flyovers

one road carried over another on concrete piers, so that neither stream of traffic stops

MakingYear 72Stands on 370 earlier

AWhat it needs

Needs 370 other products in all, 3 of them directly.

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