There is alot of serendipity in the air, regarding I'76. I have been sharing a homebrew game to some friends on BGG that is I'76 inspired. A few months back, I couldn't find many playtesters that had heard of the game (twisted metal or Vigilante 8 - yes, but I '76? - no) but it seems to be popping up alot in the nostalgic subconscious these days.
Good Old Games is now offering for purchase a downloadable version of Activision's Interstate '76 Arsenal. The package includes the original Interstate '76 game and the Nitro Pack Expansion. GOG.com also published a retrospective article about Interstate '76.