Speed cameras and red light cameras aren't unconstitutional but there is no state law allowing their use. The public is against them in most places so politicians don't want to go there. They will get voted out of office in a lot of places if they try. The US prison population has gone way up the last decade because of all the low level traffickers. They aren't even touching anyone more than 2 levels above the street corner dealer. The large cities have just gone from bad to much worse as a result.