Is it better to employ a male or female driver to transport one's wife or for getting around the city?

A woman going out with a non-mahram (definition) driver is considered forbidden khalwa (definition) (private seclusion), due to the Prophet, peace and blessings be upon him, saying: "No man is alone with a woman unless there is a mahram with her." And if it is said that her going out with him in the city and in front of people's eyes is not khalwa, this is a weak opinion and an improbable possibility, due to the harms and dangers involved. It is preferable that a woman performs this work if possible.