What vehicles are generally exempt from the ban on road traffic in "environmental zones"?

You answered correctly. In Germany, environmental zones restrict access for vehicles that do not meet certain emission standards, but there are important exceptions. Agricultural and forestry tractors, as well as ambulances on duty, are generally exempt from the ban and can enter these zones regardless of their emission class. This is because these vehicles either serve essential services or are necessary for critical work. Vehicles owned by residents of the environmental zone must still comply with the rules—being a resident alone does not provide an exemption. For future questions, remember: only certain vehicles with designated critical functions are typically exempt from environmental zone restrictions.