Ok, I installed my EU RNS-E and assumed that TMC and TP are of no use here in the US. The Traffic Message Channel is used in Europe to tell navigation devices which route to avoid and a radio station sending the Traffic Program signal broadcasts traffic messages every once in a while. Usually when you turn on TP and then scan for stations, it will only stop at a station which sends traffic messages.
So, that being said, why is my EU RNS-E showing TP and finds almost every station available here in Chicago when TP is turned on. Is there something like TP in the US? Or is the RNS-E simply confused?