Why did Romans use stones in their roads?

Answer 1

They actually weren't stones, but cobblestones. Cobblestones are shaped stone in squares and put together in a set pattern and measured . The road was leveled and the stones set in sand.

Answer 2

Concrete was used for the stone-paved road (via munita). It was used to fill the spaces between the stones to help keep them in place and to produce a flat surface. These roads were built to resist rain, freeze and flooding and to need as little repair as possible. The network of stone paved roads around the Roman Empire reached 80,500 kilometres (50,313 miles) which was 20% of the 400,000 kilometres (250,000 miles) of the total network of Roman roads in the empire.

Answer 3

No, the Romans did not use concrete to build roads. They called the stone built roads viae.