Were Roman public roads built by private companies?

Question

According to a civil engineer (video in Spanish), the Appian way was built as a concession. This is, it was built by a private "company", paid by the state.

Unfortunately, Wikipedia is not clear about who built the Appian way. It only states who "commissioned" it.

More generally, regarding public Roman roads:

Financing road building was a Roman government responsibility. Maintenance, however, was generally left to the province. The officials tasked with fund-raising were the curatores viarum. They had a number of methods available to them. Private citizens with an interest in the road could be asked to contribute to its repair. High officials might distribute largesse to be used for roads. Censors, who were in charge of public morals and public works, were expected to fund repairs suâ pecuniâ (with their own money). Beyond those means, taxes were required.

And:

Roman roads were named after the censor who had ordered their construction or reconstruction.

All this however doesn't state who built the roads.

Any expert on the topic?

Answer 1

If the question is "did the roman government officials pay individuals, slave owners and groups of workers to build construction projects instead of using the government's direct manpower?", the answer is yes, just like any other public construction work during the Roman republic, principate and empire.

If the question is "did something like Claudius & Sons Roadbuilding Inc. exist at that time that was paid to lay out, organize and execute these projects in the name of the government, with government funding?", the answer is no.

If the question is "did a rich individual pay for the first tram of the via Appia and its bordering aqueduct out of their own pocket?" the answer is yes-ish, the via was named after himself, Appius Claudius. It was not a concession nor a government instructed work though, the senate didn't even have time to debate if it was necessary when he laid out the first stones.

He was paying for it with the money granted to his political office, the Censorship, and not truly privately owned money, but it was still his to use during his "term". More importantly, nobody stopped him from doing so, his initial spending on this project gave him the surname "the blind", not because he was, but because he started investing on it without knowing if Neapolis would become a Roman colony or not in the end.

Source: The Political Aims of Appius Claudius Caecus & Wikipedia.

Answer 2

Roman roads were largely constructed by the military, at least the long distance roads between regions and cities. The legions had work crews and civil engineers attached to them for such works, as well as for building fortifications and everything else the legion would need (siege engines, barges, you name it, they'd all build it as needed where needed).

In towns and cities it'd probably be the local governments and citizens paving streets as needed and as they could afford it.

(Source)