I was driving through Illinois on I 57 just east of there at this same time. I drove through Effingham at around 11:00 AM. It was quite windy, but there was no dust at all. The thing that ‘impressed’ me the most was the plethora of Highway patrol and sheriff cars. I saw well over a half dozen. There must have been some sort of patrol concentration there. They were, obviously in the wrong place.
Just speculating. Central Illinois has had some hit and miss rain in the area. It is entirely possible I57 has been in the rain corridor while sections of I55 haven’t.