According to the Rail Procurement Agency, a metro link from Dublin Airport to St. Stephen's Green would cost almost €5 billion. For a rail link of just 10 kilometres, that figure seems off the scale in terms of affordability. We have never built a metro system in this country and have not built a major rail tunnel in almost 90 years. It is only natural, therefore, that we should approach the project in a cautious and conservative mood and seek to avoid underestimating costs and then running massively over budget but it is only natural, too, that in such circumstances we should seek to learn from others, above all our partners in the European Union. This is a particularly important point when it comes to a metro system.