Luas, meaning speed in Irish, has been 11 years in the making. In 1993 the Dublin Transport Initiative recommended construction of a £200M three-line light rail network along with expansion of the heavy rail commuter network and improvements to buses. In 1994 the Irish government gave the go-ahead and £133M funding for two light rail lines.
But by 2000 economic growth meant this plan was already out of date. A new integrated transport strategy for the Dublin area up to 2016 predicted a population growth from 1.5M to 1.75M and total peak hour trips up from 283,000 in 1999 to 488,000 in 2016.
The new strategy called for five light rail lines, three metro lines and further expansion of the heavy rail and bus networks, in all boosting capacity from 70,000 trips during the morning peak in 2000 to 300,000 by 2016.
At present two lines are being built.
Line A/C is 15km long and runs from Connolly station on the eastern side of Dublin, through the city centre on the northern bank of the River Liffey, and south west out to Red Cow and Tallaght.
About 60% is segregated; the remainder shared with other road users.
Line B is 9km long and largely follows the route of a disused railway from Sandyford in the south east to St Stephen's Green on the south side of the city centre. Plans to link up with line A/C had to be scrapped when planning permission could not be obtained for the final section through the city centre.
The plan now is to convert the line to light metro operation at a later date and drive a tunnel under the city centre, linking it with line A/C and continuing it on north of the city centre to the airport. To accommodate this the segregated part is designed for heavier axle loads.
Extensions to both lines are now in the detailed planning stage.