Opera publica is the Latin name used by Ancient Rome for the building of public works, construction or engineering projects carried out under the direction of the state on behalf of the community, and the buildings themselves. The term "public works" is a calque of the Latin. Public works in the Roman Empire were not merely buildings for the conduct of the business of running the city, but all buildings for public use. Therefore, temples, basilicae, theatres, porticoes, fora, walls of towns, aqueducts, harbours, bridges, baths, fountains, circuses, markets, cloacae, roads, etc. were classified as opera publica. In the Late Roman Empire the citizens performed opera publica in lieu of paying taxes; often it consisted of road and bridge work. Roman landlords could also demand some days' labour from their tenants, and also from the freedmen; in the latter case, the work was called opera officiales. Public works were an important department, and the Roman censors were entrusted with the expenditure of this department's public money, though the actual payments were no doubt made by the quaestors. The censors had the general superintendence of all the public buildings and works and to meet the expenses connected with this part of their duties, the Senate voted them a certain sum of money or certain revenues, to which they were restricted, but which they might at the same time employ according to their discretion. They had to see that the temples and all other public buildings were in a good state of repair, that no public places were encroached upon by the occupation of private persons, and that the aqueduct, roads, drains, etc. were properly attended to. The repairs of the public works and the keeping of them in proper condition were let out by the censors by public auction to the lowest bidder, just as the vectigalia were let out to the highest bidder. These expenses were called ultrotributa, and hence we frequently find vectigalia and ultrotributa contrasted with one another. The persons who undertook the contract were called conductores, mancipes, redemptores, susceptores, etc.; and the duties they had to discharge were specified in the Leges Censoriae. The censors also had to superintend the expenses connected with the worship of the gods, even for instance the feeding of the sacred geese in the Capitol; these various tasks were also let out on contract. The censors were in charge of keeping existing public buildings and facilities in a proper state of repair, but also constructing new ones, either for ornament or utility, both in Rome and in other parts of Italy. These works were either performed by them jointly, or they divided between them the money, which had been granted to them by the Senate. They were let out to contractors, like the other works mentioned above, and when they were completed, the censors had to see that the work was performed in accordance with the contract: this was called opus probare or in acceptum referre. The aediles had likewise a superintendence over the public buildings, and it is not easy to define with accuracy the respective duties of the censors and aediles, but it may be remarked in general that the superintendence of the aediles had more of a police character, while that of the censors were more financial in subject matter. Cicero divided the functions of the aediles under three heads: Care of provisions, care of the games and public works, which he called "care of the city". He notes responsibilities including the repair and preservation of temples, sewers and aqueducts; street cleansing and paving; regulations regarding traffic, dangerous animals and dilapidated buildings; precautions against fire; superintendence of baths and taverns; enforcement of sumptuary laws; punishment of gamblers and usurers; the care of public morals generally, including the prevention of foreign superstitions. Aediles also punished those who had too large a share of the ager publicus, or kept too many cattle on the state pastures.
