When the Mon-Fayette Expressway was conceived more than 40 years ago, the idea of a high-speed highway connecting Pittsburgh and Morgantown, W.Va., seemed like an urgent transportation and economic development need for southwestern Pennsylvania.

Since its 1973 groundbreaking, however, the toll road, still under construction, has yet to make it through its most expensive and final phase -- a Y-shaped 24-mile extension from Route 51 near Jefferson Hills to Pittsburgh and Monroeville.

Now, a group of business and political leaders is looking to jump-start the project through a public-private partnership that they hope could raise half of the estimated $3.6 billion cost.

Allegheny County Chief Executive Dan Onorato and Pittsburgh Mayor Luke Ravenstahl recently convened a closed-door meeting of more than 60 elected officials and business leaders from all corners of southwestern Pennsylvania to expedite plans to complete the Mon-Fayette Expressway.

Their objective was to find creative ways of funding the highway's northern end, which in addition to connecting Morgantown and Pittsburgh would provide a bypass to the Parkway East from Monroeville.

Their overwhelming resolution was the notion that public-private partnerships -- a marriage of private sector and government funding sources -- are the new model for funding expensive projects like this toll road.

With the project's estimated $3.6 billion to $4 billion price tag, proponents of public-private partnerships hope that regional companies with an interest in the highway's completion could foot half the bill to get the ball rolling, a significant challenge by all accounts.

At this point, however, those attending the Jan. 11 summit, including some of the region's key politicians, business leaders and economic development players, have not specified how they hope to raise that money.

But they contend that providing half of $3.6 billion would buy them the political opportunity in Harrisburg and elsewhere to sell this as a feasible project.

Mr. Onorato has empaneled a 21-member committee charged with costing out the project and getting the long-debated extension off the ground. The group will report its findings in three months.

Tom Fox, a turnpike commission manager of the Mon-Fayette and Southern Beltway Project, said the agency supports the group's efforts.

The turnpike commission, which took over the project from PennDOT and started working on the toll road in 1994, needs about $1.1 billion to finish the final design on extending the highway to Pittsburgh and the Southern Beltway project, which would connect Route 22 and Interstate 79, said Mr. Fox.

Final design, he said, includes clearances and money to buy the rights of way for the toll road and moving assets like utility lines. "We're coming pretty close. The only thing stopping us is money," said Mr. Fox.

But critics of the Mon-Fayette Expressway, who see it as an unrealistic, expensive and poorly conceived idea based on decades-old urban planning models, say this is yet another failed attempt at a pipe dream that will never see the light of day.

"This is not the first 'final push,' " said Dave McGuirk, president of Citizens for Alternatives to New Toll Roads, a group opposed to the completion of the highway.

"They have had many meetings on this road, but it is never going to happen because they just don't have the money to do it, and yet they keep making promises," said Mr. McGuirk, a longtime critic and opponent of the proposed toll road and the Pennsylvania Turnpike Commission.

A group of six staunch advocates who attended the Jan. 11 summit recently sat around a conference room table at the Monroeville Area Chamber of Commerce to discuss what they believe is the final push this project needs.

"We plan on going to Harrisburg as a team of business leaders to push legislators on this toll road because it is long overdue," said Joe Kirk, executive director of the Mon Valley Progress Council, which supports the project.

Furthermore, he added, Mon-Fayette proponents would like to see the turnpike commission issue a request for proposals on the final phase that includes public-private partnerships this year.

And unlike previous attempts, Mr. Kirk and his colleagues believe they have the momentum on their side this time to get work started on the highway.

Notwithstanding the cost and breadth of a mammoth construction project that would tear through hills, valleys and urban communities to bring the toll road to Pittsburgh, failure is not an option, they said.

This toll road must be a part of any economic revitalization efforts in southwestern Pennsylvania, said Chad Amond, president of the Monroeville Area Chamber of Commerce.

He cited the decades-long regional loss of population and industry, and the near economic death of once-thriving small towns like Duquesne, Braddock and McKeesport, as a sign of things to come for Pittsburgh and its eastern suburbs like Monroeville if the Mon-Fayette is not completed.

For his part, Mr. Onorato, who has always supported the toll road, signed onto this latest effort because of his desire to further redevelop the brownfield left by the demise of manufacturing in the valley, where he has concentrated his efforts in recent years, said spokesman Kevin Evanto.

"[Mr. Onorato] believes development in the Mon Valley needs a road connection like this highway," Mr. Evanto said. He added that Mr. Onorato was especially drawn to this effort because of "the possibility of what public-private partnerships can bring to the table."

Mr. Onorato is counting on the leadership of the business community to steer the highway's northern section to completion, said Mr. Evanto.

"There are a number of steps that this project must go through. And all we're saying right now is let's see what projections [the 21-member panel] brings back and then we will have an idea of what is feasible and what is not, and then we'll know what we can take to Harrisburg," said Mr. Evanto.

But Braddock Mayor John Fetterman, an outspoken critic of the Mon-Fayette, said it is wishful thinking to expect this toll road to make it into Pittsburgh and the Mon Valley communities.

"I don't believe it's going to happen, especially because it is bad planning at best," said Mr. Fetterman, who was not invited to the Jan. 11 summit. "All these people talk about this highway and economic development, but this is not serious economic revitalization policy."

If anything, the prospect of the Mon-Fayette, which would cut across the Monongahela River near Duquesne and meander through the Mon Valley communities of Turtle Creek, North Braddock, Braddock and Rankin among others, is stifling growth in those communities, Mr. Fetterman said.

"Many people are holding onto parcels of land that they could be developing in the hopes of cashing out when the Mon-Fayette comes, but that's never going to happen," he said.

The Mon-Fayette will kill what little economic resurgence Braddock has seen in recent years, Mr. Fetterman said. "It will not give us access to anything. We already have access. Instead, it will drive a stake through the heart of Braddock."

From his home in Jefferson Hills near Route 51, Mr. McGuirk said he often drives the finished parts of the toll road, and it is "very beautiful, but empty much of the time."

The idea of completing the toll road is analogous to the reality of what the highway is like in certain parts, he said. "It was a good idea they mismanaged, and now it's a dream."