>>1207429On the FGC (catalan govt railways) lines there's local L services, suburban S services, and R services which aren't regional but "rodalies" which means "proximity" though translated it makes little sense.
>>1207431There's just no practical reason to regauge anything. Subway line L1, which uses iberian gauge, was never re-gauged, because the subway lines are all quite isolated, so there's little benefit to it. The standard gauge subway lines have service connections, but they don't even share depots, each has their own. This allows for those neat LED thermometers, since trains can only be used on their particular line (or they need to change the LED panels first).
Just the same, there was never any useful reason to re-gauge the meter gauge system (it could be done right away, the specs indeed allow for it). Even if it were connected to other lines, it would need lots of rebuilding because specs are too different (for example low vs high platforms, 6-car trains vs 4-car on the Vallès line, 5-car on the subways), which would yeild little benefit for the expense. Mostly, since all lines are radial, the only benefit would be turning the FGC lines into a U-shaped passing system, and that would need massive re-building or train length limitations, and demand is too different on each system to make it worthwhile.
There's actually a project to extend the metre gauge line from Plaza Espanya to Gràcia station (without inter-operation), though I think it's a somewhat dumb project since it only benefits the more urban services, not the suburban ones which are unpopular because of slow speeds and lack of direct services. Essentially it's just turning this system into yet another kind of subway line, instead of making the commuter branches more competitive, for example with a new entry into the city that avoids the huge detour through Sant Boi (look at a map, the line kinda circles the city). Ironically, I'd bet anything that this will get done before the REEEEtram.
