Rulings concerning women riding with drivers and without a mahram


I am a woman who works as a student supervisor in one of the schools. The nature of my work is such that I go on trips to schools outside the city in which I work, where I go with some other women who work there, accompanied by a driver but without a mahram. What is the ruling on that, and what is the ruling on the salary I take? - knowing that my personal circumstances and my work circumstances do not allow me to have a mahram with me.