ANSWER:

If this is unavoidable then no problem in this but you must choose a seat next to a woman and try to avoid physical contact with men as much as possible and you must abide by the complete islamic hijab. 

I live in Abuja Nigeria, where we mix up with men while in the public buses or taxi the sat very close to us, many times I can’t afford to take drop only me pls what should I do, are we sinful in this mix up wit non mahram some of dem were non Muslim. I really don’t like it and it happens every day