Some of the busy subdivisions I'm referring to are the BNSF Needles Sub, Cajon Sub (some 3 MT CTC located in rural areas), UP Martinez Sub (over 100 miles of 2MT CTC) in the middle of the Sacramento Valley area, and portions of UP's Yuma Sub, all have very active radio traffic and are located in relatively rural areas. Rural area or not, it doesn't preclude the standard operating problems that active subdivisions encounter, thus the corresponding radio chatter. As for train meets, even with multi-track CTC, dispatchers will hold slower trains so that faster or higher priority trains are run around them especially if there is opposing train traffic. As for engine service, I live only a few miles from Roseville, CA with a large yard and engine servicing facility that do major overhauls and FRA inspections. Yet the power serviced there does have problems after departing the yard and there are frequent calls to UP Mechanical for help. Addressing the mobile computer maintenance of way track and time etc. requests. UP uses that system here too, yet there is considerable radio traffic regarding these types of requests and releases. We can speculate all we want about what the Marysville Sub radio traffic is like. Without being there first-hand, I'll never know. However, unless it's some magical smooth running and trouble free subdivision hosting 50 plus trains a day, I can only imagine that it would be no different than any other busy subdivision I have been to.