What is the minimum distance (in kilometers) that necessitates the presence of a mahram for a traveling woman, given that the mentioned distance is 90 kilometers?

A woman is not permitted to travel 90 kilometers without a mahram, based on the Prophet's (peace and blessings be upon him) sayings: "A woman should not travel except with a mahram," and "It is not permissible for a woman who believes in Allah and the Last Day to travel a distance of a day and a night except with a mahram." A distance of 90 kilometers is considered travel both religiously and customarily, as scholars have permitted shortening prayers (qasr), combining prayers (jam‘), and breaking the fast (iftar) for those who travel a distance of 80 kilometers. The determining factor in this is what is customarily considered travel.