Is it permissible to ride in a taxi with a non-mahram driver and with other passengers of both sexes present?

If riding a taxi within the city for errands, it is impermissible if there is a khalwa (private seclusion) between the woman and the driver. The impermissibility is negated by the presence of other people. However, if the travel is to another city, a mahram (unmarriageable kin) or husband must be present for the woman, and the presence of other people is not sufficient.