RFID tags can be read at 20-30 feet
ie: street lights
That is VERY technology dependent. Most passive tags must be placed into an active electromagnetic field at a technology characteristic frequency to pick up enough power to charge up a small capacitor and drive the transmission of the embedded numeric code. Employee ID cards tend to work only within 2 to 4 inches. The ones used in retail stores work at a 3 ft distance, thus you find the transmitter/receiver towers placed on either side of a door.
There are active devices placed on the dashboard of a car for billing of HOV lane use. Those have a 30 ft range, but are very large devices. The transceivers typically are mounted on a road sign platform at 15+ ft above the roadway.
“:RFID tags can be read at 20-30 feet
ie: street lights”
NOT if it’s wrapped in aluminum foil ...
1) One helluva field is required at that distance (I know you ppl think this is ALL magic, but, no it’s not. Physics is still applicable e.g. those governing field strengths like the inverse square law that determines field strength.)
2) What is used for ‘backhaul’ of the info to a central point? Someone had to trench in a T1 or fiber, or installed a data transceiver on some commercial or private-carrier frequency ...