The transit laws in our city do not allow buses to carry more than fifty passengers, but sometimes people break the law, and I am among the passengers who end up standing. Is there any sin on me?
If that will cause any harm, such as the one who is standing falling over, or it bothers other people because of crowding, then it is not permissible, especially if the one who is standing is a woman who finds herself in an undignified and inappropriate position, because of having to stand and be too close to men in this crowded place.
But in cases of necessity, then each case must be dealt with on its own merits, such as transferring people away from places affected by natural disasters and war.
And Allah knows best.