I've had a Garmin US/Canada safety camera database in my 1490T for a few years but only recently visited an area (large city) where warnings appeared on my unit. At first I didn't know what the unit was indicating as I was busy driving (in traffic).
Anyway now I know (from device warnings and physically seeing the camera's) where some of the POI's in the database are located. I went to those locations in BaseCamp and searched for nearby POI's (custom ones, including "safety cameras", were enabled) but no safety camera POI's showed up. This just confirms what I suspected in that these databases are "black boxes" probably so you can't route around any cameras.
PS: I was also surprised to see a number of Junction Views while traveling on the interstate in the city. I use the large JCV database.