The spatial arrangement of the main stops considered by the previous authors, reveals a significantly different distribution of sites in the territory. In our analysis, we have omitted some points that were considered very close to others, such as the case of Puente de Meyjaboy with Marzán or Iría Flavia with Padrón (Fig. 2).

If we compare these results with the starting MADO analysis, we can notice how the optimal paths connecting the territory only match with specific segments of the proposed stops. This is due to two issues: The first one is the slope of the terrain, which rises from barely 50 m at Tui to 650 m at Lugo. It is essential to consider that only 24% of the terrain is flat, with less than a 4º slope, 42% with a 4–12º slope, 21% with a 12–20º slope, and 14% of the territory with slopes higher than 20º. This general trend in the Galician territory, the heart of the area under study, makes mobility difficult, with only a few natural paths. Additionally, this implies that the MADO analysis shows indirectly the three main corridors to connect the three cities that controls the territory: Bracara Augusta, Brigantium, and Luco Augusti (as noted above) (Fig. 3). This means that the MADO model used here, provides us with the main corridors, because the geography of the terrain is quite variable in both topography and slope. The natural passes are what they are and, therefore, the chosen communication routes must be within these areas.

The second consideration is that, clearly, the topography has not been considered in the interpretations of the possible stops, as there are possibilities that are far from the main corridors. To address this, we have conducted a second analysis of them, together with cost routes. This way, the aim is connecting each potential stop to the next possibility (Fig. 4).

In this map, the optimal paths are nearly unique, at the beginning from Tude to Aquis Celenis, with only one of the possible movements considered in one case. This implies that the territory is so challenging to traverse that those options are limited. In the case of the West–East route to Luco Augusti, the problem is more significant, as there are more possibilities, along with an increased distance.

The process of proposing an optimal route has relied on topographical considerations to define the corridors. In Fig. 5, a detailed view of the beginning of the road between Tude and Burbida is shown.

In this case, by visualizing the terrain slopes and other features such as rivers, it becomes evident that mobility through the territory can only be achieved through the two corridors outlined as optimal ones. This implies that, in this particular case study, the optimal paths resemble closely the surveyor's choice, when selecting routes, because there are no other viable options. In this regard, calculating not just the antropic distance, without considering the slope but the accumulated cost with topography, means that not all paths adhere to the distance provided by the itineraries.

In Table 2, the distance correlation between different stops can be observed after the route has been corrected, according to topography.

The average distance value is longer than the theoretical mile of 1481 m, but close to that figure and relatively constant in all cases (1515–1550 m):

• Burbida, Vilar de Enfesta, 24,400 m (mile at 1525).

• Turoqua, Pontevedra, 24,500 m (mile at 1531).

• Aquis Celenis, Caldas de Reyes, 21,500 m (mile at 1535).

• Tria, La Estrada, 18,600 m (mile at 1550).

• Assegonia, Quión, 35,800 m (mile at 1556).

• Brevis, Vitiriz, 18,500 m (mile at 1541).

Up to this point, all sites are consistent with the distances, with an average deviation of about 40 m per mile. This discrepancy could be attributed to variations in the pattern or the calculation error with the optimal route, which is negligible. Therefore, we present this section without hesitation.

The problem remains unresolved at the end of this stretch, as none of the mansiones align perfectly:

• Marciae, San Román de la Retorta, 32,300 m (mile at 1615).

• Luco Augusti, Lugo, 20,500 m (mile at 1576).

We believe that San Román is the most optimal, precisely because the calculations from Luco Augusti and Brevis are the closest. The itinerary would be arranged as follows, as depicted in Fig. 6.

Based on this information, we can propose that this is the best layout, according to topography, but we need to compare it with archaeological information. By selecting archaeological elements present in the territory, and considering only those ones that provide information about a road (milestones in situ, excavated road remnants, bridges, or other elements from relevant locations such as hillforts, forts, or thermal complexes that could be potential stops on a road), we can assess the alignment. In the North–South stretch along the coast, there is no problem, due to the plenty of information provided by milestones. In the West–East stretch, we have summarised the main contributions in Fig. 7.

As can be noticed, our optimal path is very close to key landmarks in the territory, which provide information about the routes, such as the Taobada bridge, the Cuntis thermal baths (another possible mansio that would also be passed through), the toponym "A Estrada", and the Roman camp located there, the Boqueijón milestone, the Furelos bridge, and the Caligula milestone in S. Román de la Retorta. There can only be uncertainty in three cases. The first one, which is highly unlikely, is the Freixo bridge, isolated and outside from any optimal route. The second is the path to the Friol milestone, which also deviates from the main routes. Only the possibility of passing through the Curbían thermal baths, towards the milestone found in Entrambasaguas, would make sense for the route to Guntín. In this case, this possibility is less likely, since the Curbían thermal baths would not be a mansio by themselves. All these paths could well be other secondary networks that we are not aware of. Specifically, it might be worth considering whether the milestones of Friol, S. Román de la Retorta, and Entrambasaguas are not parts of the Northeast-Southwest Road that goes from A Coruña (Brigantium), to the South.

In Fig. 7, some relevant milestones associated with the territory through which the road is described have been indicated. It is undoubtedly striking that these are not located marking what would be the optimal layout proposed through the applied methodologies. The issue, without a doubt, is that the milestones can be moved. We are not referring to the fact that many of the milestones located in Gallaecia have not been found in situ, but in contexts of reuse, or they could belong to secondary branches. Therefore, when the milestone offers data on distances or cities it is a key element in the study, but for example, when they are anepigraphs their relevance is less (Rodríguez et al. 2004).