The Romans would develop road systems as they went along with their expansion. Every time they'd conquest new territory, they'd make sure to keep the new colonies controlled by facilitating access to them through the construction of new roads. In addition, the development of these routes was crucial to containing attacks and ensuring a successful defense of the Empire, as the armies would move move faster and arrive quickly to the territories in conflict.
This strategic emphasis in roads and bridges was vital to the success of their army. The routes were built specifically with speed of movement in mind, designing them mostly in straight lines for efficiency.
