Until recently, the reasonable attitude about the new South Jersey Light Rail Line seems to have been that we might as well go ahead and finish it, for all its faults.

Much money has been spent already on this. So even though the $1.2 billion project is costing more than expected and contains baffling shortcomings (it doesn't go along a particularly well-traveled route; it won't run late at night when people might actually use it to come home from the Tweeter Center), there seemed to be no reason to let all the money spent so far go to waste.

But now comes word that the major drain on taxpayer funds won't end when the project is finished, nor at any other time in the foreseeable future. Though running the line would cost nearly $70 million a year in operational costs and debt payments, fares look like they'll generate only $2.5 million.

So NJ Transit needs to study this service for the first year or two of operation and decide a sad, sad question: Will we lose more money by ending the project or by keeping it alive? If the latter, we should mentally prepare to pull the plug and cut our losses.

The reason we suggest giving the line a year or two to prove itself is that fare profits weren't the only reason the rail line has gone where it is. Planners also hoped to encourage development along that route. So part of how we judge the success of this project is by seeing whether development really does follow along.

And of course, we'd love to see the rail line succeed. We encourage everyone in South and Central Jersey to ride it and to consider the convenience of living or working along an established mass transit route.

But if commuters and developers don't show enough interest, the public should get used to the idea that this train service may simply not be worth a continuous drain on state finances, and NJ Transit should gear up to make that call.

No, we won't be glad to see a lot of empty rail cars, useless transit facilities and tracks to nowhere.

We won't exactly welcome these permanent reminders of effort and money sucked into space.

But maybe it will remind us all next time to look closely at major infrastructure projects and watch for the hand of patronage, politics and self-interest.