If the offset option's been available on NAT tracks all that time, surely the question is: Why aren't crews doing it?
Because, in from experience, many simply can't be bothered, which is why I believe it should be built in to our nav systems.
For those who want revervations, (as some have already stated in the first few posts), consider the accuracy of the current IRS/GPS systems - for instance, how often do you see opposite direction traffic NOT go exactly over or under you? - and then consider how wide an airway is. Even with an offset built in, the aircraft is going to be well within the confines of the airway.
For those with reservations, my suggestion is that the offset should 'kick in' only in RNAV, and, I'd suggest, only gradually after (say) four or five minutes or maybe even longer in that mode. If the aircraft is being vectored by a controller, it goes onto the heading called for and stays there, and if the aircraft is cleared "direct to" a waypoint after being radar vectored, I can't see a gradual introduction of a 1/2 mile offset after the first few minutes back in RNAV mode is going to make any difference to separation.
Even if it does require some ATC procedures to be modified to provide the separation demanded by the mathemeticians, surely the increase in safey margins would be worth it.
Separation can be lost sometimes, for any number of reasons, as was illustrated all too clearly by the Brazil disaster as well as a number of other earlier collisions.
I simply can't understand how few of us who fly what are quite literally speeding bullets continue to be happy, (some might say apparently blithely unaware), about having
a lot of other speeding bullets flying in exactly the same vertical plane as we are when a few lines of computer code (and some legislation) would automatically put those other speeding bullets into a completely different vertical plane.
This one step would decrease the chances of two passenger-laden speeding bullets hitting each other by an enormous degree should human error (be it a pilot's or a controller's) and/or some other problem allow a mistake to me made as it would seem was made in Brazil.