Yes you guys are on the right track with this, Ed is out of town right now but he asked me to post this explanation ....
"Essentially it’s working correctly, because Travel Mode signifies them on skis. That said, it’s probably a bit extreme to the degree that travel mode should not be much worse than walking on foot in the mud (since we can imagine that they would take off the skis and walk).
So really it’s an oversight. I’ll look into improving it in a future update, but in the meantime it’s technically working as designed (not a bug, per se, in the behavior, just not the best value used in the parameters data)."
Thanks for flagging this issue up.....