They drew highways with a ruler
Roman surveyors used rods and the groma to stake out the rigor—ruler‑straight links stretching up to 55 miles.Roman roads: How they built arrow‑straight highways
Inside the road
They excavated a fossa, packed rubble, gravel, and sometimes sand, then tamped a pavimentum. Layers followed—statumen, rudus, nucleus—and a stone summa crusta finished the surface.Roman roads: How they built arrow‑straight highways
