It was built by the emperor Trajan as an extension of the Via Appia from Beneventum, reaching Brundisium (Brindisi) by a shorter route (i.e. via Canusium, Butuntum and Barium rather than via Tarentum).

[3] Thus the Via Appia, from which Via Traiana was constructed as an extension, lost its original importance as a military highroad that connected Venosa (Venusia) and Taranto (Tarentum).

Strabo indicates correctly that traveling to Beneventum from Brundisium via the route of the later Via Traiana was a good day shorter than the old Republican road, Via Appia.

There are a number of severe hills and difficult terrain along Via Appia until it reaches Venusia which is about 66 miles (106 km) away from Beneventum.

In contrast, although Via Traiana does encounter equally demanding passages as well in the first 40 miles (64 km) from Beneventum, there is not another serious hill all the way to Brundisium.