Is it permissible for a husband to allow his wife to travel for study with her female colleagues a distance of 60 km, knowing that it is impermissible for a woman to travel without a mahram, and there is another opinion that permits it?

The majority of scholars hold that it is impermissible for a woman to travel without a mahram, except in cases of necessity. Some, however, have permitted it when there is no fear of fitna. If the wife believes it is permissible for her to travel without a mahram given her safety, then it appears the husband does not sin if he gives her permission. This is analogous to the Shafi'is and Hanbalis not preventing a man from allowing his wife to drink a small amount of nabidh if she believes it is permissible. Nevertheless, if the husband forbids his wife from traveling, she must obey him.