Like the monster in a cheap horror movie Metro North keeps coming back from the dead.
First proposed way back in the Celtic Tiger era, when there was apparently money to be had for everything, it was supposedly scrapped when the present Government took office in 2011.
Now Metro North is emerging from the tomb to which it had been so deservedly confined in 2011.
The Government is widely expected to sign off on an 'optimised', ie lower-cost, Metro North next week.
Instead of costing the €3.3bn originally budgeted, the slimmed-down Metro North will instead cost just over €2bn.
And guess what, even a lower-cost version of Metro North doesn't make sense.
Running a commuter railway all the way from St Stephen's Green to Swords via Dublin Airport would be an expensive waste of time and taxpayers' money.
This is particularly so when one considers that there is an alternative public transport project that could achieve most of what Metro North is supposed to do but much more quickly and for a fraction of the cost.
I am writing of course of the proposed spur from the existing DART line at Balgriffin to Dublin Airport.
The cost of this has been estimated at just €790m, less than half of the cost of the new, slimmed-down Metro North.
It could also be completed far more quickly, in as little as two years by some estimates.
This is because the route of the proposed DART spur would involve acquiring land from fewer than a dozen landowners and, as it already lies within the Dublin Airport planning 'sterile zone', no houses or other buildings would have to be demolished.
This seems like a no-brainer. So why has Metro North been apparently resurrected from the dead? Politics, dear reader, politics.
When Metro North was originally proposed more than a decade ago, it was no secret that one of the main driving forces behind the project was that it ran for much of its length through the Dublin Central constituency of the then-Taoiseach Bertie Ahern.
Ten years later, while Mr Ahern may have been banished (like Dart Underground), Metro North has acquired a new political sponsor.
It can hardly be any coincidence that Transport Minister Paschal Donohoe, who faces a tough battle to retain his seat in the general election that will be held in the next six-and-a-half months, also represents the Dublin Central constituency.
While we wish the minister well in his rendezvous with the voters, that's still not an excuse for resurrecting such a flawed project as Metro North.
It was a poorly-conceived project that delivered very poor value for the Irish taxpayer when it was first proposed over a decade ago, and nothing has changed in the intervening period.
So what should the Government do to improve Dublin's public transport infrastructure?
Instead of persisting with grandiose vanity projects such as Metro North and the completely insane €4bn DART Underground, which was effectively (and thankfully) scrapped by the Government earlier this week, it should focus on cheaper, quicker-to-deliver projects instead.
The DART spur to Dublin Airport is just one of these cheaper, more sensible public transport projects that are available to the Government.
Others include upgrading the existing rail link between Heuston and Connolly stations that runs under the Phoenix Park, and the construction of three new rapid bus lines at an estimated cost of €330m.
These are public transport projects that could be delivered quickly and at a reasonable cost.
Commuters would feel the benefit by the end of the decade rather than having to wait until 2030, or even later for Metro North.
The Government must wean itself off its addiction to extravagant Celtic Tiger-era public transport projects such as Metro North.
The future for Dublin's public transport lies in smart projects that get commuters moving more quickly now - not some time in the second third of the 21st century.