Among them is First Service Commercial Loans, which has said as much as $350 million in private money is available for the project.
Most recently, New Kensington's water authority agreed to allow an engineering study of its property related to the proposed commuter rail line.
Urban Innovations wants to have an engineering firm look at the property and determine the feasibility of building a rail link through it.
The link would run from Ferry Street along the Allegheny River to where the new commuter line would start near the bottom of Craigdell Road in Lower Burrell.
However, authority board members have questioned why the line would need to be built through that section of property, which has a large retention pond, a building and a water tank.
They suggested it could cost millions of dollars to go around, under or above the plant, as Urban Innovations consultant Colleen Ronzanc suggested.
Despite optimism, major obstacles remain for the project, which is more than 20 years in the making.
Finding additional funding is one of the biggest challenges, said state Rep. Eli Evankovich, R-Murrysville.
"I would never want to give the wrong impression about where things are; there are a lot of hurdles to overcome," he said. "Groups like Urban Innovations have continued to evaluate the project and figure out what needs to be done.
"I've been a staunch supporter of transforming mass transit in the Pittsburgh region to be rail-based," Evankovich said. "I would hope that if there is enough of a movement to make Pittsburgh mass transit a rail-based system that an Alle-Kiski line would be part of that."
Additionally, last January, Allegheny Valley Railroad filed a lawsuit to overturn a special zoning district that Pittsburgh City Council formed in the Strip District to help The Buncher Co. build a residential, office, hotel and retail development on a mostly vacant area between 16th and 21st streets.
Officials with the railroad believe the area still has value to them because of a long-standing easement that once gave trains access to the produce wholesalers' destination on the north side of the building.
The suit is pending in Allegheny County Court.
There also is the issue of government subsidies that likely will be needed to cover long-term operations.
Ardolino believes the train would need about 88 cents per passenger mile.
State Sen. Jim Ferlo, D-Pittsburgh, questions whether the project is sustainable.
"Ideally, there's no question we'd like to see rail and alternative transportation modes," he said.
He said there are several proposed long-term transit projects.
Specifically, he noted a proposal to replace the Parkway North HOV lanes with a monorail that would run between Pittsburgh and Cranberry.
"I think there are a lot of competing projects here," Ferlo said. "The issue is what can be done and what is sustainable."
Proponents of the line point to a 2009 feasibility study commissioned by the Westmoreland County Transit Authority that found enough potential riders for rail service on two lines, from Latrobe to Pittsburgh and from Arnold to Pittsburgh.
"I'm very positive, still, about the project," Ardolino said. "We've been working very diligently to keep it in the process."