Group Torah learning on a train

Q: Is it permissible to learn Torah in a group on the train if it may bother others?
A: It is certainly forbidden. When one travels on the train, he cannot bother others. The train is not a shul or yeshiva. If a person wants to learn, he should learn quietly. By the way, some people talk so loudly or scream on their cell phone in public and this is a severe transgression. It penetrates the private areas of another. People need proper respect for other people on a train, bus, street, etc. And this is true all the more so for one who learns Torah since "derech eretz" (proper ethical behavior) precedes Torah. The same applies to organizing a minyan on an airplane when it bothers others. The great halachic authorities ruled that it is forbidden to daven in a way which will bother others, and one should therefore daven in his own seat. They include: Ha-Rav Moshe Feinstein (Shut Igrot Moshe, Orach Chaim 4:20), Ha-Rav Shlomo Zalman Auerbach (Halichot Shlomo – Tefillah p. 95) and Ha-Rav Ovadiah Yosef. And this is how they themselves acted. El Al published a small booklet called "An Information Guide for the Religious Passenger" which includes the opinions of these great Rabbis. Ha-Rav Yosef Shalom Elyashiv also recently ruled: plane travel supersedes a minyan. There are buses in the United States rented by religious Jews where they learn Torah and daven but the main principle in our case in that it is forbidden to bother others.