The public are being asked for their opinions on a new DART Plus system that will treble passenger capacity from Maynooth to Dublin City Centre.
Minister Eamon Ryan has opened the first round of consultation on the project, which will run on the Kildare and M3 Parkway lines.
Irish Rail is also planning to run 15 trains there within four years, as opposed to the current 7.
Construction is due to begin in 2022 and it's hoped that will be finished by 2024.
The call comes as the EU confirms it will give €8.8 million for the design phase of the Dart extension to County Kildare.
€2 billion euro has been allocated to the development, which Irish Rail says will transform the rail system in the greater Dublin area.
It will link all of the rail lines and increase train frequencies and customer carrying capacity.
The DART Expansion Programme, will provide DART services as far north as Drogheda; to Hazelhatch on the Kildare Line to Maynooth in the west and to the M3 Parkway in Meath.