Dr. Brian McCann:

At peak times, the journey out of Dublin can be a major factor. In average peak weekday traffic, it would be a three-hour journey to Sligo. If there were a motorway the whole way, that could be reduced by at least 30 minutes. Galway to Dublin is a longer journey than Sligo to Dublin by the current route. In terms of travel time, however, it takes just over two hours to get from Galway to Dublin.