Also, remember that the MTA system was never designed for Wide-area coverage with Multiple sites at high elevations. Most, if not all, sites are designed to cover MTA Properties, and that's about it. They aren't monster sites; they are likely just a tower not that high next to the train tracks on a shed or something.
I understand that they are now adding some subsites around Westchester, at least, to improve coverage for those departments/areas that have terrible coverage. Ie. the West side of Dobbs Ferry, the Village of Ardsley, Parts of the town of Eastchester, the Town of Yorktown, the Town of Harrison, etc. And the reception/coverage has improved a tad recently in areas that were poor before.
Prior to Yorktown PD going online, they added a subsite on the north side of town to improve coverage there. Also, I think they are adding a site at one of the Golf Courses in the Southwest section to improve coverage there.
But basically, if you aren't near any tracks (looking at you Yorktown), you really aren't getting any coverage.
I digress...