See https://bibleatlas.org/samaria.htm

Jesus was heading from Judea back to Galilee.  Samaria was on the way, sort of.  It might look that way with a quick glance at a map.  When I personally have been in that region, however, that is not the way we have gone.  When travelling between Judea and Galilee, we’ve always gone via the Jordan Valley, using the Jericho Road, which connects that valley with Jerusalem. 

It is not too far out of the way, and I suspect for the Jewish drivers that I have been with it is also helpful not to have to go through the middle of the Palestinian areas of the West Bank.  It seems that back in Jesus’s day they did the same thing for about the same reason.  Just replace the word “Palestinian” in the previous sentence with “Samaritan.”  We might think of it as choosing street that goes through our preferred neighborhood if one way is not that much farther than the other. 

But Jesus “had to pass through Samaria.”  The chapter tells us why as we read the story.  He needed to have a conversation with a certain woman.  Before it ends, he introduces himself to her as the Messiah (4:25-26).  Speaking to his disciples, Jesus adds the somewhat cryptic remark, “Jesus said to them, “My food is to do the will of him who sent me and to accomplish his work” (4:34).  That is why he had to pass through Samaria.

Doing the will of God is not always the most convenient thing.  There may be other options.  But Jesus knew how important it was to do the Father’s will.  When planning our day, efficiency is not the only thing we should consider.  We should wonder who we might get to talk to or what we might accomplish if we remain open to the Holy Spirit’s leading – that is, open to the Father’s will.  It might not be obvious at first.

In Christ’s case, we can assume this is what he always did.  In our case, it might be something we need to start.  We might need to change our routine a little on a certain day.  There might be a woman waiting for us at a well who needs to hear about living water.