A Metro North rail line could be back on track and at a cheaper price.
The National Transport Authority is about to start a feasibility study which looks at linking up Swords, the airport and the city centre.
Director of Metro Dublin, Cormac Rabbitt, says a rail line could be built in a very short time using just 12 kilometres of underground tunnel.
The private company believes it could do it for 2 billion euro and that construction would take less than three years.
