Transport bosses are looking at extending the Luas on the north side.
The National Transport Authority is examining the prospect of extending the new luas cross city line to Finglas, Ballymun and Swords.
It would mean abandoning the Metro North project.
The extensions being looked at are along the Finglas road, Ballymun road or Drumcondra road and a 2 kilometre tunneled section between Cabra and Ballymun.
The idea will be contained in a report due to government next spring.
The NTA has already proposed a bus rapid transport scheme but admits that wouldn't cater for demand long term.
