Foggy road conditions can make it nearly impossible to see ft. in front of you

The international definition of fog is a visibility of less than 1 kilometre (3,300 ft); mist is a visibility of between 1 kilometre (0.62 mi) and 2 kilometres (1.2 mi) and haze from 2 kilometres (1.2 mi) to 5 kilometres (3.1 mi). Fog and mist are generally assumed to be composed principally of water droplets, haze and smoke can be of smaller particle size.

(d) it was complex and capable of highly organized efforts.