"Advanced Incan road-building techniques mean all your infantry move faster."—In-game description
Incan Road-building is useful for civilizations which have Home City Cards that boosts their infantry units' speed.
- The Japanese can boost their Samurai speed by 10% with the Sword Saint card, research this technology, and configure their Golden Pavilion to increase infantry movement speed even further.
- The Germans have the Tilly's Discipline technology (requires the Treaty of Westphalia card) which gives infantry 20% more speed.
- Dutch Halberdiers move quite fast (mitigating their primary weakness) when this improvement is combined with the Military Reforms card.
It can also be useful for British and Spanish, whose Thin Red Line and Corselet technologies lower the movement speed of infantry and heavy infantry by 25% and 15% in exchange for 20% and 25% more hit points. With Incan Road-building, the penalty is countered completely and the units still gain a small speed boost.