I've been listening to the Fairfax County police and fire/rescue recently and I've noticed that fairly often, I'll hear something like "show me at _______" or dispatch asking for someone's location. Do Fairfax County police and fire/rescue vehicles not have some kind of GPS transponder/tracker that shows dispatch the exact location of the vehicle? This seems like it would be a really valuable safety and accountability measure, so I was surprised when I heard locations being given by voice. Does anyone know why units would be providing their locations this way?