Presumably Nick has 'discovered' that the official method of avoiding these problems CANP, does not work. Well it never has - but is supposedly directly aimed at his problem. Perhaps some serious publicity about that issue might help?
As Maoraigh states TCAS is supposed to be being fitted - but then it was mandated in 1990 for the Tornado fleet and is still years away (if ever).
Having said that on the Canadian West coast there are area radio frequencies which are used for route and position reporting. Given the often rather low ceiling this means many operators have to use passes in the mountains and islands and fly through the letterbox, and it is standard practice to give a radio call when approaching and leaving these choke points. That works pretty well but the areas are fairly small - from memory 40-ish miles.