Is it permissible for a woman to travel in an elevator alone with a non-mahram man?

Allaah has forbidden a man to be alone with a woman who is
not his mahram. The Prophet (peace and blessings of Allaah be upon him)
said: “No man is alone with a woman but the shaytaan is the third one
present.” Narrated by al-Tirmidhi (1171); classed as saheeh by al-Albaani in
Saheeh al-Tirmidhi. 

Al-Bukhaari (1862) and Muslim (1341) narrated that the
Prophet (peace and blessings of Allaah be upon him) said: “No man
should be alone with a woman unless her mahram is with her.” 

Al-Nawawi (may Allaah have mercy on him) narrated in Sharh
Muslim (14/153) that there is scholarly consensus that it is haraam for
a man to be alone with a non-mahram woman. This was also mentioned by
al-Haafiz in al-Fath (4/77). 

What is meant by a man being alone with a woman is that they
are alone together in a place with no one else present. 

This meaning applies when a woman travels in an elevator with
a man who is not her mahram and there is no one else with them, whether it
is open or closed. 

Based on that, it is not permissible for a woman to travel in
an elevator on her own with a non-mahram man. If there is one or more other
women with her, then there is nothing wrong with her travelling on the
elevator in that case, because then she is not alone with the man. 

If there are both men and women with her, there is nothing
wrong with her travelling on it if the elevator is spacious, and she will
not be forced to touch or rub against the men. But in this case it is safer
for the Muslim woman to walk up the stairs, and seek reward with Allaah for
the difficulty that she encounters by doing that, because she is only doing
that so as to avoid that which Allaah has forbidden and to avoid fitnah and
its causes. 

And Allaah knows best.