We do not use GURPS hiking RAW, Instead we use a variant.
Distance traveled per day is 5 x move in miles.
Successful hiking still increases distance by 20%
A group lead by someone with Leadership at 12+ May make a single roll against the group’s average hiking skill.
If this roll is made the group agrees not to split up.
Terrain and weather
Good (perfect roads and clear weather) are x1
Average (rolling hills, light woods, drizzle) are x.80
Bad conditions (forest, heavy rain, hot day) are x.50
The worst combinations (Forest and heavy rain) are x.20
Break down of day and fatigue costs
It’s assumed a day of travel is 8 hours of walking and 2 hours of resting to balance fatigue costs.
With two proper meals in the day (+ 2 FP) and 2 hours of rest in ten minute blocks throughout the day (+ 12 FP) combined with the 8 hours of hiking (-2 FP/ hour of hiking). you end up with a net – 2 fatigue. (- 16FP + 14FP)