The PIIGS are possibly more reliant on road transport than average, something stemming from geographic location, inappropriate Urban Planning or both.

Or a historic lack of capital to invest in railways when they were fashionable. All those states invested in infrastructure when railways were silly socialism.

Ireland has a crappy railway infrastructure and really great social attitudes to use of public transport: Sam's colleagues in her more status conscious job used to be somewhat horrified that she commuted by rail rather than driving. We've upgraded the existing infrastructure,  but built relatively little - a light transit system in Dublin. There was far more rail fifty years or so ago.