There are three models for the trusted traveller system. The first is the simplifying passenger travel initiative, which is being run by IATA, the International Air Transport Association, which has connected technology companies, airports, and governments to provide essentially an express route between London and Hong Kong so that your travel credentials follow you through the airport.
The second is the national version, which is like the NEXUS or the CANPASS, in which both countries' police forces agree on a number of security checks. This is always linked to biometric information, because while one's documents can be changed, it's hard to change one's retina or one's iris or one's face for verification.
The third is the kind that is in place at Ben Gurion, at Schiphol, that has been tried in the United States, which is airport-specific systems, where one does not apply for the aviation system as a whole but rather for specific airports. The “Privium” system at Schiphol airport and the “Clear” program in the United States are airport-run. There are also checks, but they are local rather than national.