We understand why lawmakers can't figure out a way to pay for the massive amount of road work that needs to be done in Maine: There just isn't enough money to do it and it's likely there will never be.

Here's a radical idea for legislators: Maine can't afford the roads it has.

At 8,500 miles, the system is just too big and far-flung and expensive for our relatively poor state to maintain. We agree with Bangor Democratic Sen. Joe Perry, who asked his colleagues bluntly, "Is 8,500 miles too much road system for us to afford and do too many of those roads go through too rural areas of Maine, and the cost of building them to standards too high or even maintaining them, and should we just decommission a percentage of the roads?"

Since the 2008 legislative session, lawmakers have been struggling to find a way that's effective and politically palatable to pay for the growing and alarming backlog of road repair and reconstruction. They've debated a gas tax, they've looked at a complex scheme to establish a trust fund based on tax revenues, they've considered tolls and even installing devices on cars to measure how much you drive and then taxing that.

They've also heard that the poor state of Maine's roads is taking a personal as well as widespread economic toll, most recently in a report issued this week by the respected Maine Development Foundation.

"These bridges and highways serve as critical links for Maine communities, and every day that we let them fall into further disrepair costs us lost lives, lost income and lost economic potential," says economist Laurie Lachance, head of the foundation.

But the discussion of how to pay for the backlog of maintenance and repair avoids the question that should be asked first: Can Maine pay for all its roads?

So the discussion is an essentially conservative one -- it takes as a given that what we have in front of us is what we must do, because that's how we've always done it.

The long list of deferred road maintenance began growing before this recession and will continue to grow after the recession -- it is not an artifact of our current hard times. In its zeal over the past few decades to upgrade rural roads, to pave every dirt road, to widen and rebuild every country byway so that it met modern standards, the state took on too much. It was politically popular to do -- but economically unsustainable.

Now, though, reality demands that we contract our road spending to match the capacity of the state's economy to support it. Yes, our economy depends in large part on a safe, high-quality road system. But by reaching for too much, we can't keep up with even the most basic maintenance; the Department of Transportation just last month canceled $30 million of paving projects across the state.

Can we envision a healthy Maine economy based on a limited, high-quality road system?

We must.

The contraction of our state-maintained road system -- and the attendant public outrage -- is not something for politicians to do. The welfare of individual politicians is, in part, based on how many potholes they have in their district. This is too crucial a task to place in the hands of those whose political future depends on satisfying voters. That's why it's been so hard for lawmakers to fashion a solution to the problem so far.

What Maine needs is an independent commission to tackle this problem and make an up-or-down recommendation to the Legislature and governor. Its members should come from business, from the academic world and other fields -- anyone but politicians. Former transportation commissioners could be members, as could former political figures.

Maine needs to solve this problem, but a realistic appraisal of the state's financial capacity means that it can't solve this problem without significant short-term pain. In the end, the entire state will benefit from the shift to a well-run road system that can carry goods and people safely and efficiently.

Getting there, though, is the biggest part of the problem.