It would allow for electrified rail from Glasnevin, through Heuston Station to Hazelhatch and Celbridge in Kildare
Planning permission has been granted to expand the DART network in Dublin.
It would allow for electrified rail from Glasnevin, through Heuston Station to Hazelhatch and Celbridge.
Transport Minister Eamon Ryan says it will increase capacity and reduce journey times on intercity and commuter services.