I drove IL 394 today. Its south end includes a short multiplex with IL 1, before reaching the End 394 sign about where the HB has it at Goodenow Rd. Both OSM and Google Maps show the IL 1/IL 394 multiplex.
I suggest adding an IL394_N point to the IL 1 file, and IL1_N to the IL 394 file, at the northern IL 1/IL 394 junction. Also, in IL 1, IL394 => IL394_S, and in IL 394, IL1 => IL1_S (keep and hide the old labels).