How did Roman use of arches differ from Greek post-and-lintel construction?

In Western architecture, the primary difference between the Roman use of the arch and the Greek post-and-lintel system lies in how they manage structural loads and span space.

Structural Mechanics

• Post-and-Lintel: This system relies on vertical supports (posts) holding up a horizontal beam (lintel). Because stone is weak in tensile strength, lintels must be short to prevent breaking under their own weight or the load they carry.12
• The Arch: An arch is a curved member that redirects vertical loads into diagonal forces, known as thrust. By using wedge-shaped blocks called voussoirs, the arch converts downward pressure into compressive force, which pushes the blocks together rather than apart.34

Architectural Impact

• Span and Scale: While the Greeks primarily used post-and-lintel construction for monumental architecture, the Romans fully exploited the arch to span much wider openings using smaller, lighter materials.34
• Spatial Freedom: The arch allowed Romans to create complex, large-scale structures like aqueducts, bridges, and vast interior spaces covered by vaults and domes, whereas Greek architecture remained largely defined by the formal simplicity of columns and beams.456