hey, I did that song for my assignment as well.
It's not really about a physical journey (I'm assuming you want to know about how it relates to them?) but about how he feared nuclear war. Dylan wrote it in 1962 when the Cuban Missile Crisis was at its peak.
However, I still used it for my assignment coz' it's a pretty good song, and if done well, makes sense in relation to physical journeys! I said that it was showing how physical journeys show us the bad things that occur in the world, but they make us realise that something has to done about it so that everything will work out right - only I said it a bit more sophisticated than that.
There are tonnes of techniques in it! Some of them are: symbolism, repitition, anaphora, word choice - i.e. negative connotations, irony, personification, alliteration, sensory imagery. But don't forget to talk about the actual music as well.
Hope that helps you.