Rail is the longer term option that Ireland will eventually follow as is happening in the rest of Europe. The road building lobby in Ireland is sufficiently powerful still to ensure that the bulk of investment goes into roads which is why ther is an imbalance. This is the reason that you have high rise car parks at Dublin airport without a rail connection even though when the M50 was being developed it would have been easy to run a spur from either the Belfast line or the Sligo line. The western rail corridor is a vital piece of infrastructure that is owned by the state which could never be put in place today and should be developed to reconnect the west particularly to Rosslare port. Rail links to our ports have been gradually severed, the truck lobby was more influential.
Today rail links are operating from Europe to China making that option faster that the sea routes on the One Belt One Road corridors. This is the future.