When I started being involved with Sports Car Club of America events at IRP back in the 1980's, the SCCA race officials and IRP track operations, safety, and maintenance staff were using 151.625, 151,925, and 154.600 MHz.
But, the track staff quit using VHF some time ago and started using UHF around 462 MHz. Don't know if they got licenses for those frequencies or if they were using rented radios. The SCCA corner workers also switched to UHF in the 462 range, too, though the race officials were still using 154.600. At one time, there was an off-site airport parking company that had a repeater with the output on 151.625 (yes, not allowed, but they were doing it anyway) which made use of that frequency at IRP pretty much useless for anyone in the control tower at the track. When the SCCA raced out there, we used IRP wreckers and ambulances, so it made it pretty handy for everyone to be on UHF. At one time, I had a list of frequencies, but it's been 2-3 years since I was involved in any SCCA events at LOR/IRP, so I've had no reason to interface with those folks.
My guess is that NHRA is using UHF also. They probably have a nationwide license for a few frequencies. The track people may be using the same freqs.
