Many shorter bridges, especially in rural areas where they may be exposed to water overtopping and corrosion, utilize concrete box girder.

Due to the properties of the second moment of area, the height of a girder is the most significant factor to affect its load capacity.

These designs allow bridges to span larger distances without requiring the depth of the beam to increase beyond what is practical.

As technology advanced the methods were improved and were based on the utilization and manipulation of rock, stone, mortar and other materials that would serve to be stronger and longer.

The bridges constructed by Romans were at the time basic but very dependable and strong while serving a very important purpose in social life.