As things have been since release, overland travel can get annoying when the enemy constantly takes the party by surprise even if the party has Perception and Survival as skills. Even Rangers in their Natural Explorer terrain suffers from this and the only reliable ways to deal with it I've found are Oblivion Clerics and a level 7 Barbarians. I think there is something wrong with a Ranger with proficiency in Stealth, Perception and Survival routinely failing to notice enemies when in their favored terrain.
Some suggestions:
1. Make Rangers immune to surprise in overland travel in their favored terrain, much like the Oblivion Cleric is immune to surprise when at camp.
2. Add a feat that helps with surprise. Given that we only get 3-4 stat increases in this game, spending one of them to help avoid surprise is probably fairly balanced.
3. Make it so that overland encounters can start with neither side surprised. For example, if the party is immune to surprise or doesn't roll more than X above the enemy, neither side is surprised when combat begins.
Typos happen. More so on the phone.