Which is an improvement king darius made to his empire?

An improvement King Darius made to his empire is the creation roads. Daríus I the Great worked to restore order in the empire, carried out an administrative reform and implemented a type of monetary economy that encouraged the development of local commerce. At the same time it restructured the Empire dividing it into twenty administrative and legal units. He was the one who indicated that roads were built that united his city with all the administrative units; He also created an efficient postal system, in addition to promoting again the belief in Persian religion with protection to local cults.