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Why is stone especially useful for bridge arches and piers?

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bridge The multiple-span Seto Great Bridge over the Inland Sea, linking Kojima, Honshu, with Sakaide, Shikoku, Japan.

Stone is particularly useful for bridge arches and piers because it is exceptionally strong in compression, which is the primary force acting upon these structural elements.12

In an arch bridge, the downward load forces the wedge-shaped stones, known as voussoirs, tightly together. This mechanism allows the structure to support significant weight and span much wider openings than would be possible with horizontal stone beams, which are prone to failure because stone is weak in tension.21

For piers, stone's compressive strength provides the necessary stability to support the vertical loads of the bridge and to buttress the horizontal thrust generated by the arches. Because stone can be fashioned into smaller, manageable blocks, it allows for the construction of massive, durable foundations that can withstand environmental stresses over centuries, as evidenced by ancient Roman structures that remain standing today.23