The romans built many roads, all being almost ruler straight to construct their impressive roads they used a number of instruments.

 

One of the first instruments used in the process of mapping out a road was a groma. A groma is a long wooden staff, it would be set for markers of the road during building and with the naked eye surveyors would determine if it was straight.

 

A rudimentary spirit level aka a chorobates, was used when leveling out the land or producing a steady incline dioptras were also used during this process. The libra was also used to measure gradients later a hodometer was used for measuring distances, from that they produced mile markers to count easily how long the road was.

 

The roman surveyors were responsible for gthe work of the roads, the romans did not come up with the original methods of road building but they did refine it greatly.