Is it permissible for a man to stand behind another man with physical contact between them in public transportation?

Touching between men in areas other than the 'awrah (private parts) is permissible, provided it is devoid of lust or the intention of lust. As for touching the 'awrah, it is forbidden if there is lust or if there is no barrier. It is disliked even with a concealing garment if lust is absent and not intended. The dislike is removed in cases of necessity, provided there is no lust and no fear of temptation.