I read in Canon 1197. that parish priest can give dispansion to travellers. If I would go into another town for only one day and if I had a opportunity to dispense my vow at my parish, would I be considered a traveller?
That’s what it means.
The point is that the pastor has jurisdiction over everyone within his own territory, (unless the law says otherwise). Therefore, the moment you enter his parish territory, he can dispense you.