What is the ruling on a woman riding alone in a limousine (taxi) within Riyadh, knowing that she is compelled to do so due to the absence of a mahram and to fulfill the needs of her family?

It is not permissible for a woman to be alone with a man who is a stranger to her in a car, due to the saying of the Prophet, peace and blessings be upon him: "No man is alone with a woman unless there is a mahram with her." A woman's going out to work is permissible if she is compelled to spend on herself and her father. She must fear Allah and seek employment specifically for women. If she can only find mixed-gender work, then it is permissible for her due to necessity. She must take measures to avoid being alone with the driver, such as seeking work close by or sharing a ride with a female colleague.