Mixed seating or traveling on public transportation during rush hour when it is impossible to avoid contact with women.

Igros Moshe (E.H. 2:14): Question: Mixed-seating on a subway or other public transportation at a time of day that it is impossible not to come in contact with women because of the crowding of people going to work. Is it permitted to travel at that time. Answer: As regarding the forced contact with women there is absolutely no sin since it is not the result of lust  and passion. The basic prohibition of with contact with women is only when it is done in a lustful manner as he learns from the verse lo tikravu. So if not done in a lustful manner there is no prohibition even rabbinically as can be seen from the Shach regarding a Nidah taking the pulse of her husband. .It is standard practice for Jewish doctors to take the pulse of women who are Niddah even if they are married or not Jewish.  .  In sum there is no prohibition if not done in a lustful manner – even rabbinical;ly. Therefore there is nothing to be concerned about travelling on public transportation during rush hour when because of the crowding it is impossible to avoid contact with women. Similarly there is no prohibition to sit next to a woman if there is no other place since it is not done in a lustful manner. Even sitting next to one’a wife who is Nidah is permitted according to the majority of achronim  who agree with the Shach. However anyone who knows that any contact with women causes lustful thoughts should avoid it if possible.  If he must travel then to get to his work it is still permitted but he should try and distract himself from the women and prohibited thoughts and think about Torah. However if he knows he is basically evil and will be sexually aroused it is prohibited to travel even to his work. But G-d forbid! that a person should be that way since it typically is the result of idleness. Therefore he should increase his Torah and work to change this.