Final answer:
Pi had metaphorically traveled a challenging and narrow "road" at sea, which represents the treacherous currents or sections of the ocean that made his journey difficult.
Step-by-step explanation:
After his ordeal at sea, Pi finds out he had traveled through a challenging and narrow "road," which in the context of the question, refers metaphorically to the difficulties he faced while navigating a treacherous part of the ocean. This narrow "road" can be inferred as a difficult sea current or a part of the sea beset with challenges that made his travel difficult and progress towards the shore arduous. Similarly, the passages provided discuss different challenges faced by individuals either at sea or while traveling, and these challenges can be seen as metaphorical roads that the characters have to navigate.