Which construction challenge primarily restricted expansion of Roman roads into Alpine regions?

💡 Explanation

When temperatures fall below freezing in Alpine regions, frost heave occurs because water expands upon freezing within the roadbed's porous matrix, destabilizing the road structure through cyclic stress. Therefore, roadbed instability results, rather than labor shortages, materials, or surveying issues which also posed limitations to a lesser extent.

• Which agricultural consequence arose when chinampas utilized hydraulic soil consolidation in the Valley of Mexico?
• Which mechanical consequence results when a 19th-century steam engine's cylinder lubrication system fails?
• Which structural failure mode was most common in poorly designed Roman arches built on unstable ground?
• Which advantage did properly cambered Roman roads provide during periods of heavy rainfall?
• Which navigational outcome occurred when medieval Islamic astrolabes incorporated horizon-based coordinate systems at sea?
• Which outcome reduces long-term structural integrity when early Mesopotamian ziggurats experience repeated freeze-thaw cycles?