Hej Nordmenn!

THis will be a lot more diffcult as last yr, as you now hit the 3 most difficult countries for IR-pass; ESpana-then FR-then IT and in that order as 1 - 2 - 3. But as such the route you mention is not the hardest-luck with bad news.

In fact-IF you are willing to use the slower regional trenes, yo can do it till IT without any need to RES-very much like NSB/Vy lokaltaget around Oslo. But if you really want the hi-speed TGV etc, then you do need to RES and will face problems-about garanteed. The trick is to change from the ES broad gauge to normal in the old borderstop Cerbere or Port Bou. UNtill Nice these all run about ev 1 or 2 hrs.

Others, like often dear anna b fra Sverige will also follow up and give links to make these RES-you may have seen it already. For IT-you can use IC-toget all the way and make RES (indeed can do nearly always a day or 2 before) via oebb.at (Austria rail).

There ARE a very few trains Vnz-.Ljubl-but there may be works along part of this line, which is pretty scenic in SLO. Change Trieste. As such no need for bussen.

You now come in old Yugoslavija. Indeed in my own exp I prefer Lju a lot above Zag (not that much to see nor do). VERY limited trains from there to coast-end at Split.NO trains at all along coast and hence also not to Dubr. BUS is never included in the pass-always pay, most are now easily booked online-actually in fact a lot easier as many pesky Train RES.

NO trains at all over borders between HR-Rsb, Srb-Mac and Mac-GR- IF really very adventurous you could go via Albania, its bus in any case, but quite a long trip and not overly comfy. If not interested in these areas-fly over (check WIZZair) or 2x ferries to/fro Italy to GR-but then you end at ´wrong´ side of GR for all the other islands.

There have been several recent posts about GR isles and a possible pass-I eave it to there and others to inform you-or post more clear questions for that. For me a FERRYpass looks like more trouble as it will deliver in possible discount

In my opinion Interrailing in Spain. France and Italy gets an undeserved bad press. Whilst each requires a pragmatic approach to reservations, once understood and followed they are as good as any. 

Spain has a spectacular high speed network between cities and a good Medium Distance network. Whilst pre reserving is not easy the general feedback is waiting until you arrive and doing it at main stations is fairly straightforward and rarely is a train full. When full there is usually an alternative within a few hours.

Similarly France has an excellent TGV network supported by a good regional service. The only concern I have is the introduction of a low cost TGV network that is not in the Pass network (Ouigo). Making reservations is simple using the B-europe site. Yes domestic TGVs (InOui) cost either 10 or 20 euro this is clear and we have the choice to look for alternative routings.

I find the negative comments on Italian Trenitalia the strangest as in all my travels they have been the easiest to get reservations (either by OEBB or the Eurail reservation website. Their high speed network (Freccia) is expansive and the regional/Intercity sytstem is frequent and comfortable. Again reservation fees are clear and at 3 (IC) or 10 (Freccia) euros reasonable when compared to the full on the day fare.

I agree that there are operators who make it much simpler for Interrailing, but once you understand the intricacies and differences between operators and routings you can make your plans with confidence.