You can probably pick up ISP District 10 off one of the County feeds on Broadcastify. District 10 encompasses Champaign County, Douglas County (Tuscola) and Coles County (Charleston/Mattoon). The Illinois State Police has gone to regional dispatch centers and I think District 10 is handled by Pontiac. The District 10 cars still use X identifier (like X-47) since there are so many 10 codes.
Champaign County which emcompasses Champaign City, Urbana, Rantoul abd several other small towns are on their own P25 Motorola system which is very easy. You might catch more ISP traffic on the Coles or Douglas County feed.