I would recommend fast-forwarding through most of a long journey by road, concentrating on any interesting encounters. Road travel should normally be routine, even in a fantasy world - if every journey was interrupted by orcs and manticores few people would ever get to their destination. Describing the changing scenery is nice, but forcing people to play through every minute of the trip sounds like a boring waste of time to me.
If the party are travelling through a dangerous environment, it's worth taking longer over the journey. Where I might say "Over the next 10 days you travel 500 miles along the Sakbe Highway...", if the party is struggling through high snowy mountains at 5 miles/day I'll make sure they feel how difficult it is with plenty of Climb checks, Survival checks, opportunities for disaster through falls and other accidents, as well as describing the notable scenery each day: "Climbing up out of the Valley of Bones across a bleak scree-strewn slope, a dark cavern looms ahead to your left, while along the ridgeline above you a huge boulder reminiscent of a giant's skull is silhouetted against the glowering sky..."
If the party are travelling through a dangerous environment, it's worth taking longer over the journey. Where I might say "Over the next 10 days you travel 500 miles along the Sakbe Highway...", if the party is struggling through high snowy mountains at 5 miles/day I'll make sure they feel how difficult it is with plenty of Climb checks, Survival checks, opportunities for disaster through falls and other accidents, as well as describing the notable scenery each day: "Climbing up out of the Valley of Bones across a bleak scree-strewn slope, a dark cavern looms ahead to your left, while along the ridgeline above you a huge boulder reminiscent of a giant's skull is silhouetted against the glowering sky..."