It seems like a lot of them have quietly shut IBOC off recently. WJR 760 and WABC 770 were about the worst case scenario, and turned it off first. As I recall, they calculated that it raised their effective NIF contours to 14 mV/m. In Michigan, you could hear WABC IBOC interference to WJR in the Daytime, before Nighttime operation was even allowed, and it started during Critical Hours, and suddenly stopped at NYC Sunset. WABC's analog signal wasn't even that strong. When WSB shut theirs off, the mid 700s were an oasis of skywave signals. I'll have to check WBBM to see if they shut it down. The Detroit area stations besides WJR kept theirs until recently because they were the demonstrator test market for the car radio market. Some made no sense, 1 kW Class IVs/Cs and a 500 watt Day two site operation with 14 watts Night which didn't have it at the Night Site. I guess the chip shortage was the final straw. The Detroit Area IBOC stations interfered with the licensed Daytime service areas of stations 10 kHz and even 20 kHz adjacent. At least one station owner that was being interfered with even during CH skywave and with a very low power PSSA that was being interfered with by a 10 kHz adjacent, and they sold the station because of it.