Road to 60 doubles your EXP gain on everything including doubled rested EXP, doubledd food EXP buff etc.
So you will get different boni for different situations like:
Quests: +100%
Rested EXP: +100%
Food: 6%
Armoury <60/>60: +200%/+100%

Without Road to 60 you won't get a bonus on quests and the rest is just half as high.