RoadRailers on UP Milwaukee Sub

Lately I’ve been seeing RoadRailers on the UP Milwaukee Sub (I live in Des Plaines, just south of DeVal) - but only the tail end; never made it in time to see what power was hauling them. Does anyone know who’s operating them, and what power they’re run with, through this area?

I think its NS power, not sure. I think I herd something about that here in NJ.

They’ve been running since July or so; usually a UP SD70M in the 5000-5280 number series or the 3800-series. Sometimes they will get an NS loco, however. The trains are from NS in Chicago to Proviso, to East Minneapolis for an auto-parts (factory?)

Their symbol is ZCHEM for north/westbound and ZEMCH for the south/eastbounder

I think I remember eading about this in train magazine it coulb be both up and ns power who knows