Bill, welcome to iRV2.com. We are glad to have you join us here and we look forward to reading of your adventures and experiences. I am sure you will enjoy this website.
The road is probably causing the air ride valves to release air on the high side of the suspension as you travel and the compressor will cycle on and off to re-pressurize the tank(s). I am surprised that you can hear the pop off of the regulator or filter drier as you are driving. As long as the coach is not having a problem such as listing or dropping ride height I guess you are operating as per design.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7