was the road that led from Rome to the Portus Trajani, or the new port of the city constructed under the Empire on the right bank of the Tiber. [OSTIA
] The name could not, of course, have come into use until after the construction of this great artificial port to replace the natural harbour of Ostia, and is only found in the enumeration of the Viae in the Curiosum Urbis and Notitia (pp. 28, 29, ed. Preller).
But the line of the road itself may still be traced without difficulty.
It issued from the Porta Portuensis, in the walls of Aurelian, and followed, with little deviation, the right bank of the Tiber, only cutting off the minor windings of that river. The Antonine Itinerary places the city of Portus 19 miles from Rome (p. 300); but this is certainly a mistake, the real distance being just about the same as that of Ostia, or 16 miles. (Nibby, Dintorni,
vol. iii. p. 624.) From Portus a road was carried along the coast by Fregenae (9 miles) to Alsium (9 miles), where it joined the VIA AURELIA